Basic Routing Problem... Setting up new lab at home...

Hi Everyone,

I've been busy and not in the forums as of late, but I'm re-dedicating time to moving forward with my certs again.

Tonight, I have a 2821 router that has several interfaces...

WLC#show ip int b
Interface IP-Address OK? Method Status Protocol
GigabitEthernet0/0 unassigned YES manual up up
GigabitEthernet0/0.10 172.16.10.1 YES manual up up
GigabitEthernet0/0.50 172.16.50.1 YES manual up up
GigabitEthernet0/1 10.0.0.250 YES manual up up
Serial0/0/0 unassigned YES unset administratively down down
In1/0 172.16.1.1 YES manual up up
In1/0.2 172.16.2.1 YES manual up up
In1/0.3 172.16.3.1 YES manual up up
In1/0.100 172.16.100.1 YES manual up up
Loopback2 2.2.2.2 YES manual up up

The In1/0 and subinterfaces are a Wireless Lan Controller that I've setup in this router.

My default gateway is...

Gateway of last resort is 10.0.0.1 to network 0.0.0.0

2.0.0.0/32 is subnetted, 1 subnets
C 2.2.2.2 is directly connected, Loopback2
172.16.0.0/24 is subnetted, 6 subnets
C 172.16.50.0 is directly connected, GigabitEthernet0/0.50
C 172.16.10.0 is directly connected, GigabitEthernet0/0.10
C 172.16.1.0 is directly connected, Integrated-Service-Engine1/0
C 172.16.2.0 is directly connected, Integrated-Service-Engine1/0.2
C 172.16.3.0 is directly connected, Integrated-Service-Engine1/0.3
C 172.16.100.0 is directly connected, Integrated-Service-Engine1/0.100
10.0.0.0/24 is subnetted, 1 subnets
C 10.0.0.0 is directly connected, GigabitEthernet0/1
S* 0.0.0.0/0 [1/0] via 10.0.0.1

...and I can ping my gateway of 10.0.0.1 (which is my Comcast cable modem). I can also ping outside.. ie. 4.2.2.2

My problem is that I can NOT ping using a different source. For example, if I type...

ping 4.2.2.2 source 172.16.1.1

..it times out.

There are vlans setup on my switch. It pings fine without the "source" added on to the end. Adding a source and it no longer pings...

Any suggestions that might assist me?

Thanks!
-Paul

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Comments

networker050184

I'm assuming your Comcast router only knows about the 10.0.0.0 range attached to it's inside interface and also might only be set up to NAT that. So with no route back or a NAT it's bound to fail with any other source address.

zeetskeet

Can you ping your gateway using the src command?

shortstop20

networker050184 wrote: »

I'm assuming your Comcast router only knows about the 10.0.0.0 range attached to it's inside interface and also might only be set up to NAT that. So with no route back or a NAT it's bound to fail with any other source address.

This is correct.

ptlinva

Hi Everyone,

Sorry for the delayed response. Yes, it was due to Comcast also natting out. Therefore, once I natted at my router, things started routing fine. However, I then ordered FIOS with a static IP and connected all of my equipment from Comcast and life has been a lot better as far as getting things working.

In fact, I'm having a blast with my new WLC working. I can't wait to get some Cisco phones ringing across my network now. -= big grin =-

Thanks to all!
Your friend,
Paul