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Any IP Experts ?? I have some tricky traceroute Questions



 
 
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  #1  
Old October 13th 03, 03:49 PM
gn107001
external usenet poster
 
Posts: n/a
Default Any IP Experts ?? I have some tricky traceroute Questions

I have a Linksys Router connected to my PC, wich is then connected to
a Hub LAN port1, and the hub's LAN port1 is connected to my Cable
Modem via a crossover cable. It works perfectly now, but without the
hub the signal levels would not cooperate. Anyway, the hub, using two
LAN ports, should be transparent and not show up as a hop with
diagnostics. I have 6 questions below - if anyone can help me I would
really appreciate it.

Setup
--------

The router's control panel say's it's IP LAN address is 192.168 1.1
and it's IP WAN address is 68.232.136.159. It say's it's default
gateway is 68.232.136.1

The Cable Modem's control panel says it's Ethernet IP addr is
192.168.100.1 (for the port facing me). It does not list it's WAN
port IP address.

Question 1 - shouldn't the router's default gateway be the cable
modem's Ethernet port, at 192.168.100.1 ??

I have been trying to verify the far side addresses of the Router and
Cable modem. Trace will not do it (it lists near side addresses
only). But I did use it to verify the reported near side addresses.
Here are the odd results. Many IP addresses are showing up as 1 hop
away !! I though that the only address that is one jop is the cable
modem (192.168.100.1), since it is on the other side of my router.

But I am getting a Class A "10" address that keeps showing up for some
traces, and for others it does not show up. Weird - here are the
traceroutes and the questions.

TraceRoutes and Questions
---------------------------------------------
Starting trace - Oct 13, 2003 09:09:30
Tracing to 67.20.47.45....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 67.20.47.45 9
Host reached
Question 2 - why does the router's IP address of 192.168.1.1 not show
here? Why does the cable modem's IP address of 192.168.100.1 not show
here?

Starting trace - Oct 13, 2003 09:09:44
Tracing to 67.20.47.46....
Hops IP Address RTT(ms) DNS Name
1 67.20.47.46 11
Host reached
Question 3 - why does this route not show the address 10.175.192.1 ??
It appears to be a router owned by Adelphia, and it has a near and far
interface to me, with the addresses .45 and .46 The trace shows the
..45 address as 2 hops and it must go through the Class 10 address, but
for the .46 address it is one hop away and does not go through the
Class A 10 address.

Starting trace - Oct 13, 2003 09:10:44
Tracing to 68.168.17.109....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 67.20.47.45 10
3 68.168.17.109 12
Host reached

Starting trace - Oct 13, 2003 09:11:07
Tracing to 68.168.17.110....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 68.168.17.110 8
Host reached

Starting trace - Oct 13, 2003 09:18:27
Tracing to 192.168.100.1....
Hops IP Address RTT(ms) DNS Name
1 192.168.100.1 2
Host reached
Question 4 - this is the near side of the Cable Modem, which is indeed
1 hop away. I wonder why for all traceroutes "beyond" this point,
they do not show the address 192.168.100.1 in the path ??

Starting trace - Oct 13, 2003 09:19:05
Tracing to 10.175.192.1....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
Host reached
Question 5 - this is that mysterious 10 address. I have no idea which
device this belongs to. Maybe the router, since it is performing
NAT??

Starting trace - Oct 13, 2003 09:19:55
Tracing to 192.168.1.1....
Hops IP Address RTT(ms) DNS Name
1 192.168.1.1 0
Host reached
Here I am tracing the directly connected Router LAN port - it shows up
here, but not in any traceroutes beyong this point.

Tracing to 68-232-136-1.chvlva.adelphia.net [68.232.136.1]....
Hops IP Address RTT(ms) DNS Name
1 68.232.136.1 7
68-232-136-1.chvlva.adelphia.net
Host reached
Question6 - this is the first router that I am connected to via my own
Linksys router and then Cable modem. Why does it show up as 1 hop -
like it is directly connected? Why does my own router and my own
cable modem not appear? Also, why does that 10 address not show up,
like it did with all my other traceroutes that went outside my own LAN
??

Lastly, for those who want to see - here is a long trace to
mindspring. Once again, it goes through 10.175.192.1

Starting trace - Oct 13, 2003 07:23:44
Tracing to pop.mindspring.com [207.69.200.184]....
Hops IP Address RTT(ms)
1 10.175.192.1 6
2 67.20.47.45 9
3 68.168.17.109 13
4 24.48.9.153 13
5 66.109.6.133 12
6 66.109.0.109 16
7 66.109.0.166 18
8 66.109.1.138 17
9 206.223.115.32 22
10 209.86.82.34 31
11 207.69.223.158 30
12 209.86.66.18 31
13 TIMED OUT
14 207.69.200.184 30 smith.mail.mindspring.net
Host reached

Ads
  #2  
Old October 13th 03, 04:23 PM
Kip Patterson
external usenet poster
 
Posts: n/a
Default



gn107001 wrote:
I have a Linksys Router connected to my PC, wich is then connected to
a Hub LAN port1, and the hub's LAN port1 is connected to my Cable
Modem via a crossover cable. It works perfectly now, but without the
hub the signal levels would not cooperate. Anyway, the hub, using two
LAN ports, should be transparent and not show up as a hop with
diagnostics. I have 6 questions below - if anyone can help me I would
really appreciate it.

Setup
--------

The router's control panel say's it's IP LAN address is 192.168 1.1
and it's IP WAN address is 68.232.136.159. It say's it's default
gateway is 68.232.136.1

The Cable Modem's control panel says it's Ethernet IP addr is
192.168.100.1 (for the port facing me). It does not list it's WAN
port IP address.

Question 1 - shouldn't the router's default gateway be the cable
modem's Ethernet port, at 192.168.100.1 ??

I have been trying to verify the far side addresses of the Router and
Cable modem. Trace will not do it (it lists near side addresses
only). But I did use it to verify the reported near side addresses.
Here are the odd results. Many IP addresses are showing up as 1 hop
away !! I though that the only address that is one jop is the cable
modem (192.168.100.1), since it is on the other side of my router.

But I am getting a Class A "10" address that keeps showing up for some
traces, and for others it does not show up. Weird - here are the
traceroutes and the questions.

TraceRoutes and Questions
---------------------------------------------
Starting trace - Oct 13, 2003 09:09:30
Tracing to 67.20.47.45....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 67.20.47.45 9
Host reached
Question 2 - why does the router's IP address of 192.168.1.1 not show
here? Why does the cable modem's IP address of 192.168.100.1 not show
here?

Starting trace - Oct 13, 2003 09:09:44
Tracing to 67.20.47.46....
Hops IP Address RTT(ms) DNS Name
1 67.20.47.46 11
Host reached
Question 3 - why does this route not show the address 10.175.192.1 ??
It appears to be a router owned by Adelphia, and it has a near and far
interface to me, with the addresses .45 and .46 The trace shows the
.45 address as 2 hops and it must go through the Class 10 address, but
for the .46 address it is one hop away and does not go through the
Class A 10 address.

Starting trace - Oct 13, 2003 09:10:44
Tracing to 68.168.17.109....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 67.20.47.45 10
3 68.168.17.109 12
Host reached

Starting trace - Oct 13, 2003 09:11:07
Tracing to 68.168.17.110....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 68.168.17.110 8
Host reached

Starting trace - Oct 13, 2003 09:18:27
Tracing to 192.168.100.1....
Hops IP Address RTT(ms) DNS Name
1 192.168.100.1 2
Host reached
Question 4 - this is the near side of the Cable Modem, which is indeed
1 hop away. I wonder why for all traceroutes "beyond" this point,
they do not show the address 192.168.100.1 in the path ??

Starting trace - Oct 13, 2003 09:19:05
Tracing to 10.175.192.1....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
Host reached
Question 5 - this is that mysterious 10 address. I have no idea which
device this belongs to. Maybe the router, since it is performing
NAT??

Starting trace - Oct 13, 2003 09:19:55
Tracing to 192.168.1.1....
Hops IP Address RTT(ms) DNS Name
1 192.168.1.1 0
Host reached
Here I am tracing the directly connected Router LAN port - it shows up
here, but not in any traceroutes beyong this point.

Tracing to 68-232-136-1.chvlva.adelphia.net [68.232.136.1]....
Hops IP Address RTT(ms) DNS Name
1 68.232.136.1 7
68-232-136-1.chvlva.adelphia.net
Host reached
Question6 - this is the first router that I am connected to via my own
Linksys router and then Cable modem. Why does it show up as 1 hop -
like it is directly connected? Why does my own router and my own
cable modem not appear? Also, why does that 10 address not show up,
like it did with all my other traceroutes that went outside my own LAN
??

Lastly, for those who want to see - here is a long trace to
mindspring. Once again, it goes through 10.175.192.1

Starting trace - Oct 13, 2003 07:23:44
Tracing to pop.mindspring.com [207.69.200.184]....
Hops IP Address RTT(ms)
1 10.175.192.1 6
2 67.20.47.45 9
3 68.168.17.109 13
4 24.48.9.153 13
5 66.109.6.133 12
6 66.109.0.109 16
7 66.109.0.166 18
8 66.109.1.138 17
9 206.223.115.32 22
10 209.86.82.34 31
11 207.69.223.158 30
12 209.86.66.18 31
13 TIMED OUT
14 207.69.200.184 30 smith.mail.mindspring.net
Host reached


The cable modem operates as a bridge. You will never see its addresses
in a trace route unless you are tracing to the modem itself. in fact,
you won't even see its hardware address. The hardware you will see in
the ARP tables will be that of the CMTS, which is the 10.x.x.x address
you mentioned.

Many home routers ignore ICMP packets, so they don't appear in the
traceroutes, either.

I can't account for why the CMTS appears sometimes and not others. The
..45 and .46 addresses you mention are on the same subnet, so they are
not likely to be opposite sides of a router - since a router is not
needed in that situation.

Kip

  #3  
Old October 13th 03, 04:39 PM
gn107001
external usenet poster
 
Posts: n/a
Default

Thanks -

What does CMTS stand for ?

On Mon, 13 Oct 2003 14:23:11 GMT, Kip Patterson
wrote:



gn107001 wrote:
I have a Linksys Router connected to my PC, wich is then connected to
a Hub LAN port1, and the hub's LAN port1 is connected to my Cable
Modem via a crossover cable. It works perfectly now, but without the
hub the signal levels would not cooperate. Anyway, the hub, using two
LAN ports, should be transparent and not show up as a hop with
diagnostics. I have 6 questions below - if anyone can help me I would
really appreciate it.

Setup
--------

The router's control panel say's it's IP LAN address is 192.168 1.1
and it's IP WAN address is 68.232.136.159. It say's it's default
gateway is 68.232.136.1

The Cable Modem's control panel says it's Ethernet IP addr is
192.168.100.1 (for the port facing me). It does not list it's WAN
port IP address.

Question 1 - shouldn't the router's default gateway be the cable
modem's Ethernet port, at 192.168.100.1 ??

I have been trying to verify the far side addresses of the Router and
Cable modem. Trace will not do it (it lists near side addresses
only). But I did use it to verify the reported near side addresses.
Here are the odd results. Many IP addresses are showing up as 1 hop
away !! I though that the only address that is one jop is the cable
modem (192.168.100.1), since it is on the other side of my router.

But I am getting a Class A "10" address that keeps showing up for some
traces, and for others it does not show up. Weird - here are the
traceroutes and the questions.

TraceRoutes and Questions
---------------------------------------------
Starting trace - Oct 13, 2003 09:09:30
Tracing to 67.20.47.45....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 67.20.47.45 9
Host reached
Question 2 - why does the router's IP address of 192.168.1.1 not show
here? Why does the cable modem's IP address of 192.168.100.1 not show
here?

Starting trace - Oct 13, 2003 09:09:44
Tracing to 67.20.47.46....
Hops IP Address RTT(ms) DNS Name
1 67.20.47.46 11
Host reached
Question 3 - why does this route not show the address 10.175.192.1 ??
It appears to be a router owned by Adelphia, and it has a near and far
interface to me, with the addresses .45 and .46 The trace shows the
.45 address as 2 hops and it must go through the Class 10 address, but
for the .46 address it is one hop away and does not go through the
Class A 10 address.

Starting trace - Oct 13, 2003 09:10:44
Tracing to 68.168.17.109....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 67.20.47.45 10
3 68.168.17.109 12
Host reached

Starting trace - Oct 13, 2003 09:11:07
Tracing to 68.168.17.110....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 68.168.17.110 8
Host reached

Starting trace - Oct 13, 2003 09:18:27
Tracing to 192.168.100.1....
Hops IP Address RTT(ms) DNS Name
1 192.168.100.1 2
Host reached
Question 4 - this is the near side of the Cable Modem, which is indeed
1 hop away. I wonder why for all traceroutes "beyond" this point,
they do not show the address 192.168.100.1 in the path ??

Starting trace - Oct 13, 2003 09:19:05
Tracing to 10.175.192.1....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
Host reached
Question 5 - this is that mysterious 10 address. I have no idea which
device this belongs to. Maybe the router, since it is performing
NAT??

Starting trace - Oct 13, 2003 09:19:55
Tracing to 192.168.1.1....
Hops IP Address RTT(ms) DNS Name
1 192.168.1.1 0
Host reached
Here I am tracing the directly connected Router LAN port - it shows up
here, but not in any traceroutes beyong this point.

Tracing to 68-232-136-1.chvlva.adelphia.net [68.232.136.1]....
Hops IP Address RTT(ms) DNS Name
1 68.232.136.1 7
68-232-136-1.chvlva.adelphia.net
Host reached
Question6 - this is the first router that I am connected to via my own
Linksys router and then Cable modem. Why does it show up as 1 hop -
like it is directly connected? Why does my own router and my own
cable modem not appear? Also, why does that 10 address not show up,
like it did with all my other traceroutes that went outside my own LAN
??

Lastly, for those who want to see - here is a long trace to
mindspring. Once again, it goes through 10.175.192.1

Starting trace - Oct 13, 2003 07:23:44
Tracing to pop.mindspring.com [207.69.200.184]....
Hops IP Address RTT(ms)
1 10.175.192.1 6
2 67.20.47.45 9
3 68.168.17.109 13
4 24.48.9.153 13
5 66.109.6.133 12
6 66.109.0.109 16
7 66.109.0.166 18
8 66.109.1.138 17
9 206.223.115.32 22
10 209.86.82.34 31
11 207.69.223.158 30
12 209.86.66.18 31
13 TIMED OUT
14 207.69.200.184 30 smith.mail.mindspring.net
Host reached


The cable modem operates as a bridge. You will never see its addresses
in a trace route unless you are tracing to the modem itself. in fact,
you won't even see its hardware address. The hardware you will see in
the ARP tables will be that of the CMTS, which is the 10.x.x.x address
you mentioned.

Many home routers ignore ICMP packets, so they don't appear in the
traceroutes, either.

I can't account for why the CMTS appears sometimes and not others. The
.45 and .46 addresses you mention are on the same subnet, so they are
not likely to be opposite sides of a router - since a router is not
needed in that situation.

Kip


  #4  
Old October 14th 03, 12:18 PM
DougNews
external usenet poster
 
Posts: n/a
Default

Here's a quick CMTS explanation -
http://www.techweb.com/encyclopedia/...term?term=CMTS - and a site to
explain some cable modem troubleshooting:
http://homepage.ntlworld.com/robin.d...ips/index.html


gn107001 wrote in message
...
Thanks -

What does CMTS stand for ?



  #5  
Old October 14th 03, 02:56 PM
Ken
external usenet poster
 
Posts: n/a
Default

I am trying to figure out each component of my Cable Modem Internet
access out of curiosity and learning benefit only. My previous post
was answered and I now know the Router and Cable modem are transparent
and that is why they do not show up in my TraceRoutes. It is odd that
the router is transparent, since it is a router and definitely add one
hop . . . but OK.

What I cannot figure out is why no paths go through my cable modem's
default gateway !!

Default Gateway
---------------------------
In my Router's control panel, it lists the default gateway as
68.232.136.1 - I thought that must be the Cable modem, but no. The
cable modem is 192.1.100.1 - so I I did a lookup on the default
gateway address:

Starting lookup on 68.232.136.1 - Oct 14, 2003 08:21:47
Official Name: 68-232-136-1.chvlva.adelphia.net
IP address: 68.232.136.1

It is named like an Adelphia POP (chvlva.adelphia.net). The CMTS
would be near my house. So the default gateway should be "beyond" the
CMTS. So I also traced the default gateway:
Starting trace - Oct 14, 2003 08:21:56
Tracing to 68.232.136.1....
Hops IP Address RTT(ms) DNS Name
1 68.232.136.1 7
68-232-136-1.chvlva.adelphia.net
Host reached

One hop - no passage through the CMTS.

Remote Trace-Routes
-----------------------------------
All remote traceroutes that I perform, do pass through the CMTS, but
none pass through the default gateway !!! Weird. Here is a sample
trace:

Starting trace - Oct 14, 2003 08:01:10
Tracing to www.usatoday.com [66.54.32.240]....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 67.20.47.45 10
3 68.168.17.109 15
4 24.48.9.153 14
etc
etc

So why does the trace to my default gateway, which appears to be in an
Adelphia POP (by it's name) - fail to pass through the CMTS? As
you can see, it shows up as one hop away, and never hits the "10"
address of the CMTS? Maybe it has a direct, separate link to the
Adelphia POP, and bypasses the CMTS ?

Also, my DNS server trace, unlike the default gateway - does pass
through the CMTS - but again - it does not pass through the default
gateway:

Starting trace - Oct 14, 2003 08:40:02
Tracing to 24.51.159.130....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 67.20.47.45 8
3 68.168.17.109 13
4 24.48.9.214 12
5 24.51.159.130 13 nscache1.chvlva.adelphia.net
Host reached

My IPconfig /all
--------------------------
If it helps, here is my IPconfig /all. I see one interesting line:
"Connection-specific DNS Suffix . : chvlva.adelphia.net"
This is the same suffix as my default gateway, which is
68.232.136.1 (68-232-136-1.chvlva.adelphia.net)
and my DNS server is
24.51.159.130 (nscache1.chvlva.adelphia.net)
So they should be located in the same POP, but the trace to the
default gateway shows it as one hop away, and the the DNS server is 5
hops. Anywhere here is my ipconfig /all output:


Windows IP Configuration

Host Name . . . . . . . . . . . . : dad
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection 3:

Connection-specific DNS Suffix . : chvlva.adelphia.net
Description . . . . . . . . . . . : 3Com OfficeConnect 10/100
Physical Address. . . . . . . . . : 00-04-75-B5-A7-4B
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.1.102
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
DHCP Server . . . . . . . . . . . : 192.168.1.1
DNS Servers . . . . . . . . . . . : 24.51.159.130
24.51.159.133
24.51.159.130
Primary WINS Server . . . . . . . : 127.0.0.1



On Mon, 13 Oct 2003 14:23:11 GMT, Kip Patterson
wrote:



gn107001 wrote:
I have a Linksys Router connected to my PC, wich is then connected to
a Hub LAN port1, and the hub's LAN port1 is connected to my Cable
Modem via a crossover cable. It works perfectly now, but without the
hub the signal levels would not cooperate. Anyway, the hub, using two
LAN ports, should be transparent and not show up as a hop with
diagnostics. I have 6 questions below - if anyone can help me I would
really appreciate it.

Setup
--------

The router's control panel say's it's IP LAN address is 192.168 1.1
and it's IP WAN address is 68.232.136.159. It say's it's default
gateway is 68.232.136.1

The Cable Modem's control panel says it's Ethernet IP addr is
192.168.100.1 (for the port facing me). It does not list it's WAN
port IP address.

Question 1 - shouldn't the router's default gateway be the cable
modem's Ethernet port, at 192.168.100.1 ??

I have been trying to verify the far side addresses of the Router and
Cable modem. Trace will not do it (it lists near side addresses
only). But I did use it to verify the reported near side addresses.
Here are the odd results. Many IP addresses are showing up as 1 hop
away !! I though that the only address that is one jop is the cable
modem (192.168.100.1), since it is on the other side of my router.

But I am getting a Class A "10" address that keeps showing up for some
traces, and for others it does not show up. Weird - here are the
traceroutes and the questions.

TraceRoutes and Questions
---------------------------------------------
Starting trace - Oct 13, 2003 09:09:30
Tracing to 67.20.47.45....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 67.20.47.45 9
Host reached
Question 2 - why does the router's IP address of 192.168.1.1 not show
here? Why does the cable modem's IP address of 192.168.100.1 not show
here?

Starting trace - Oct 13, 2003 09:09:44
Tracing to 67.20.47.46....
Hops IP Address RTT(ms) DNS Name
1 67.20.47.46 11
Host reached
Question 3 - why does this route not show the address 10.175.192.1 ??
It appears to be a router owned by Adelphia, and it has a near and far
interface to me, with the addresses .45 and .46 The trace shows the
.45 address as 2 hops and it must go through the Class 10 address, but
for the .46 address it is one hop away and does not go through the
Class A 10 address.

Starting trace - Oct 13, 2003 09:10:44
Tracing to 68.168.17.109....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 67.20.47.45 10
3 68.168.17.109 12
Host reached

Starting trace - Oct 13, 2003 09:11:07
Tracing to 68.168.17.110....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 68.168.17.110 8
Host reached

Starting trace - Oct 13, 2003 09:18:27
Tracing to 192.168.100.1....
Hops IP Address RTT(ms) DNS Name
1 192.168.100.1 2
Host reached
Question 4 - this is the near side of the Cable Modem, which is indeed
1 hop away. I wonder why for all traceroutes "beyond" this point,
they do not show the address 192.168.100.1 in the path ??

Starting trace - Oct 13, 2003 09:19:05
Tracing to 10.175.192.1....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
Host reached
Question 5 - this is that mysterious 10 address. I have no idea which
device this belongs to. Maybe the router, since it is performing
NAT??

Starting trace - Oct 13, 2003 09:19:55
Tracing to 192.168.1.1....
Hops IP Address RTT(ms) DNS Name
1 192.168.1.1 0
Host reached
Here I am tracing the directly connected Router LAN port - it shows up
here, but not in any traceroutes beyong this point.

Tracing to 68-232-136-1.chvlva.adelphia.net [68.232.136.1]....
Hops IP Address RTT(ms) DNS Name
1 68.232.136.1 7
68-232-136-1.chvlva.adelphia.net
Host reached
Question6 - this is the first router that I am connected to via my own
Linksys router and then Cable modem. Why does it show up as 1 hop -
like it is directly connected? Why does my own router and my own
cable modem not appear? Also, why does that 10 address not show up,
like it did with all my other traceroutes that went outside my own LAN
??

Lastly, for those who want to see - here is a long trace to
mindspring. Once again, it goes through 10.175.192.1

Starting trace - Oct 13, 2003 07:23:44
Tracing to pop.mindspring.com [207.69.200.184]....
Hops IP Address RTT(ms)
1 10.175.192.1 6
2 67.20.47.45 9
3 68.168.17.109 13
4 24.48.9.153 13
5 66.109.6.133 12
6 66.109.0.109 16
7 66.109.0.166 18
8 66.109.1.138 17
9 206.223.115.32 22
10 209.86.82.34 31
11 207.69.223.158 30
12 209.86.66.18 31
13 TIMED OUT
14 207.69.200.184 30 smith.mail.mindspring.net
Host reached


The cable modem operates as a bridge. You will never see its addresses
in a trace route unless you are tracing to the modem itself. in fact,
you won't even see its hardware address. The hardware you will see in
the ARP tables will be that of the CMTS, which is the 10.x.x.x address
you mentioned.

Many home routers ignore ICMP packets, so they don't appear in the
traceroutes, either.

I can't account for why the CMTS appears sometimes and not others. The
.45 and .46 addresses you mention are on the same subnet, so they are
not likely to be opposite sides of a router - since a router is not
needed in that situation.

Kip


  #6  
Old October 14th 03, 04:15 PM
Nicholas Suan
external usenet poster
 
Posts: n/a
Default

Ken wrote in :

I am trying to figure out each component of my Cable Modem Internet
access out of curiosity and learning benefit only. My previous post
was answered and I now know the Router and Cable modem are transparent
and that is why they do not show up in my TraceRoutes. It is odd that
the router is transparent, since it is a router and definitely add one
hop . . . but OK.

What I cannot figure out is why no paths go through my cable modem's
default gateway !!

Default Gateway
---------------------------
In my Router's control panel, it lists the default gateway as
68.232.136.1 - I thought that must be the Cable modem, but no. The
cable modem is 192.1.100.1 - so I I did a lookup on the default
gateway address:

Starting lookup on 68.232.136.1 - Oct 14, 2003 08:21:47
Official Name: 68-232-136-1.chvlva.adelphia.net
IP address: 68.232.136.1

It is named like an Adelphia POP (chvlva.adelphia.net). The CMTS
would be near my house. So the default gateway should be "beyond" the
CMTS. So I also traced the default gateway:



Your default gateway is the CMTS.


So why does the trace to my default gateway, which appears to be in an
Adelphia POP (by it's name) - fail to pass through the CMTS? As
you can see, it shows up as one hop away, and never hits the "10"
address of the CMTS? Maybe it has a direct, separate link to the
Adelphia POP, and bypasses the CMTS ?


What you have to understand here is that a device on the internet can have
more than one IP address. Your CMTS is just replying with its primary
address in the 10.0.0.0/8 range instead using the address of the network
that your computer is is on. In fact, if you were to look at the hardware
address they would be the same for 68.232.136.1 and 10.175.192.1. The only
time it is going to respond with 68.232.136.1 is when you send it packets
directly addressed to 68.232.136.1.


Also, my DNS server trace, unlike the default gateway - does pass
through the CMTS - but again - it does not pass through the default
gateway:

Starting trace - Oct 14, 2003 08:40:02
Tracing to 24.51.159.130....
Hops IP Address RTT(ms) DNS Name
1 10.175.192.1 8
2 67.20.47.45 8
3 68.168.17.109 13
4 24.48.9.214 12
5 24.51.159.130 13 nscache1.chvlva.adelphia.net
Host reached

My IPconfig /all
--------------------------
If it helps, here is my IPconfig /all. I see one interesting line:
"Connection-specific DNS Suffix . : chvlva.adelphia.net"
This is the same suffix as my default gateway, which is
68.232.136.1 (68-232-136-1.chvlva.adelphia.net)
and my DNS server is
24.51.159.130 (nscache1.chvlva.adelphia.net)
So they should be located in the same POP, but the trace to the
default gateway shows it as one hop away, and the the DNS server is 5
hops. Anywhere here is my ipconfig /all output:



The connection-specific DNS suffix is the suffix that gets addeded to a
name when you type in to make it a fully-qualified domain name, so if you
were to to type in "mail", "chvlva.adelphia.net" would be tacked on the end
before your computer looked it up from the DNS server.
  #7  
Old October 15th 03, 12:03 AM
Giles Harney
external usenet poster
 
Posts: n/a
Default


Ken wrote in message ...

What I cannot figure out is why no paths go through my cable modem's
default gateway !!


it does.

different address same device.


  #8  
Old October 15th 03, 01:14 AM
Ken
external usenet poster
 
Posts: n/a
Default

Oh, OK.

Hmmmm - the 10. address is usually for NAT and/or PAT, but when I have
seen it, it was behind a Cisco PIX or similar device, and supported
multiple users - each had a different 10.x.x.x address. But that was
it as far as I was aware of - no 2nd address for each user. Maybe
there were two addresses for each user, but it was not stated in the
network documentation (this was for T1 Internet customers when I
worked at Sprint).

I guess there must be multiple users on each CMTS. But not sure why
they use two addresses for the same interface. As far as my router is
concerned, it only reports knowing about the DHCP assigned
68.232.136.1 address. But since a trace shows 10.175.192.1 and does
not show 68.232.136.1 - then apparently my router, even though it's
default gateway is 68.232.136.1 - it is instead forwarding to
10.175.192.1 - same interface, but odd that it selects a different
IP address, other than it's default gateway.

On Tue, 14 Oct 2003 18:03:24 -0400, "Giles Harney"
wrote:


Ken wrote in message ...

What I cannot figure out is why no paths go through my cable modem's
default gateway !!


it does.

different address same device.


 




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