Re: ISR 1100 connectivity problem - Page 2

Sakura · ‎04-19-2023

Hi,

I'm trying to configure a ISR 1111 with two internet connections (one for backup).

Until now, VLAN 200 (Ge0/1/2 to Ge0/1/7 + WLANGe0/1/8) are accessing to internet by Cel0/2/0 (working correctly).

Now, I have a new connection (initiated by dhcp) on Ge0/0/0.

I've configured Ge0/0/0 with DHCP and is working, but I cannot get to internet on these interface.

I've attached running conf.

#sh ip route
Gateway of last resort is 0.0.0.0 to network 0.0.0.0

S* 0.0.0.0/0 is directly connected, Cellular0/2/0
2.0.0.0/32 is subnetted, 1 subnets
C <public> is directly connected, Cellular0/2/0
172.26.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.26.254.0/24 is directly connected, Vlan1
L 172.26.254.1/32 is directly connected, Vlan1
192.168.0.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.0.0/24 is directly connected, GigabitEthernet0/0/0
L 192.168.0.33/32 is directly connected, GigabitEthernet0/0/0
192.168.10.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.10.0/24 is directly connected, Vlan200
L 192.168.10.1/32 is directly connected, Vlan200

#sh ip inter brief
Interface IP-Address OK? Method Status Protocol
GigabitEthernet0/0/0 192.168.0.33 YES DHCP up up
GigabitEthernet0/0/1 unassigned YES NVRAM administratively down down
GigabitEthernet0/0/1.2 10.134.101.141 YES NVRAM administratively down down
GigabitEthernet0/0/1.3 unassigned YES NVRAM administratively down down
GigabitEthernet0/0/1.6 unassigned YES unset administratively down down
GigabitEthernet0/1/0 unassigned YES unset down down
GigabitEthernet0/1/1 unassigned YES unset down down
GigabitEthernet0/1/2 unassigned YES unset down down
GigabitEthernet0/1/3 unassigned YES unset down down
GigabitEthernet0/1/4 unassigned YES unset up up
GigabitEthernet0/1/5 unassigned YES unset down down
GigabitEthernet0/1/6 unassigned YES unset up up
GigabitEthernet0/1/7 unassigned YES unset down down
Wl0/1/8 unassigned YES unset up up
Cellular0/2/0 <public> YES IPCP up up
Cellular0/2/1 unassigned YES NVRAM administratively down down
Dialer6 unassigned YES NVRAM administratively down down
Tunnel0 192.168.10.1 YES unset up up
Virtual-Access1 unassigned YES unset up up
Vlan1 172.26.254.1 YES NVRAM up up
Vlan200 192.168.10.1 YES NVRAM up up

Ping test:

#ping 8.8.8.8 source G0/0/0
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 8.8.8.8, timeout is 2 seconds:
Packet sent with a source address of 192.168.0.33
.....
Success rate is 0 percent (0/5)

#ping 192.168.0.1 source G0/0/0
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.0.1, timeout is 2 seconds:
Packet sent with a source address of 192.168.0.33
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms

Part of the configuration are created from web interface. If I connect a computer on the cable of G0/0/0 (instead of cisco router) I got IP (on 192.168.0.0/24) and I have internet access.

mawillis · ‎04-24-2023

One other thought is that maybe the ISP blocks 8.8.8.8 because they want to force use of their DNS. Can you ping 8.8.8.8 from the computer that gets the 34 address? You might need to change your sla/track to a different ip.

Sakura · ‎04-25-2023

I've checked, now my ISP doesn't allow ping to any host. I've checked and I have internet now but ping fails to any destination IP.

I need to check if connection are working on Cisco router without the ping, and try to configure SLA without ICMP.

mawillis · ‎04-25-2023

So now you know why the SLA fails. You could try pinging the first router in the ISP's network, the one upstream from your domestic router.

Sakura · ‎04-26-2023

Hi,

I've changed SLA for testing the DHCP server on ISP network and now works correctly.

Also, I've removed the domestic router from the network and I've connected cisco to the media converter. Now I have an IP of range 100.0.0.0/8.

But I have a problem:

When I have a default route defined by interface, connection does not work. I need to create a route with the next-hop IP address to get it working.

On my previous config, I have this:

ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0/0 name primary track 1

That does not work to get the VLAN200 to internet or pinging ISPs devices.

I've changed to this new line:

ip route 0.0.0.0 0.0.0.0 100.64.107.1 name primary track 1 <-- (IP obtained from sh dhcp lease, my IP are 100.64.107.147)

With this config connection works, I can ping ISP dhcp server without problems and can get to internet (from computer on VLAN200).

The problem are: How can I change this to be dynamic? If tomorrow I'll receive a new IP from another /24 (for example, 100.64.108.147) maybe the gateway will change and I'll need to update the router configuration.

Richard Burts · ‎04-26-2023

Thanks for the update. Glad to know that SLA is now working

For default route try this: ip route 0.0.0.0 0.0.0.0 dhcp

HTH

Rick

Sakura · ‎04-27-2023

route with dhcp doesn't allow me to add track.

(config)#ip route 0.0.0.0 0.0.0.0 dhcp 1 ?
<cr> <cr>

Richard Burts · ‎04-30-2023

It is unfortunate that ip route specifying dhcp does not allow using track. Perhaps a solution might be an EEM script which could look for changes in SLA state and could remove/add the dhcp default route?

HTH

Rick