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MightyMikeyFlag for United States of America

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Cisco 1921 point-to-point communication issues

I have set up two Cisco 1921 routers. One is setup at our main branch and the second one is set up at sister branch a few buildings down the road. Lets call main branch Router 1 and sister branch Router 2.

I can communicate and ping computers at the sister branch from the main branch, but I cannot communicate and ping computers at the main branch from the sister branch.

When I set up the routers the first time. I set them up side by side. I could ping router to router. I hooked up a laptop to each router and could ping each computer as well.

Is there anything I am missing? What could be causing this?

Other config is pretty much the same except service-module is set to Line.

Here is the config:

Using 1448 out of 262136 bytes
!
! Last configuration change at 19:23:45 UTC Mon Nov 15 2010
!
version 15.0
service timestamps debug uptime
service timestamps log uptime
service password-encryption
!
hostname ************
!
boot-start-marker
boot-end-marker
!
enable secret *********************
enable password ***************
!
no aaa new-model
!
!
!
!
no ipv6 cef
ip source-route
ip cef
!
!
!
!
no ip domain lookup
!
multilink bundle-name authenticated
!
!
!
license udi pid CISCO1921/K9 sn *********!
!
!
redundancy
!
!
!
!
!
!
!
!
!
interface GigabitEthernet0/0
 ip address 192.168.6.251 255.255.255.0
 duplex auto
 speed auto
 no mop enabled
 !
!
interface GigabitEthernet0/1
 no ip address
 shutdown
 duplex auto
 speed auto
 !
!
interface Serial0/0/0
 ip address 192.168.101.253 255.255.255.0
 no fair-queue
 no clock rate 2000000
 service-module t1 clock source internal
 service-module t1 timeslots 1-24
 service-module t1 remote-alarm-enable
 !
!
router rip
 version 2
 network 192.168.6.0
 network 192.168.7.0
 network 192.168.100.0
 network 192.168.101.0
 no auto-summary
!
ip default-gateway 192.168.6.250
ip forward-protocol nd
!
no ip http server
no ip http secure-server
!
ip route 0.0.0.0 0.0.0.0 192.168.6.2
ip route 0.0.0.0 0.0.0.0 192.168.6.250
!
!
!
!
!
!
snmp-server community public RO
snmp-server enable traps tty
!
control-plane
 !
!
!
line con 0
line aux 0
line vty 0 4
 password *********
 login
!
scheduler allocate 20000 1000
end

Avatar of John Meggers
John Meggers
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What subnet is on the LAN side at the other?  Is that the 192.168.7.0?  If so, there's no reason to list it in the RIP configuration on this router, you generally only list subnets you are actually advertising from a given router.  

Are you receiving RIP updates from the other side? You can do a debug RIP and find out. You're also not advertising a default route over the serial link, are you using a static default at the other end?  I take it there are no ACLs in the way on the other side.
Avatar of Istvan Kalmar
Hi,

why did you configured two default routes?

ip route 0.0.0.0 0.0.0.0 192.168.6.2
ip route 0.0.0.0 0.0.0.0 192.168.6.250

you need the following
router rip
 redist static
what shows the following on booth sides?

sh ip int brief
sh ip route
Avatar of MightyMikey

ASKER

@ikalmar (second repsonse)

Router 1 at main branch:
sh ip int brief shows:

Interface                  IP-Address      OK? Method Status                Protocol
GigabitEthernet0/0         192.168.6.251   YES NVRAM  up                    up

GigabitEthernet0/1         unassigned      YES NVRAM  administratively down down

Serial0/0/0                192.168.101.253 YES NVRAM  up                    up

sh ip route shows:

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, + - replicated route

Gateway of last resort is 192.168.6.2 to network 0.0.0.0

S*    0.0.0.0/0 [1/0] via 192.168.6.2
      192.168.6.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.6.0/24 is directly connected, GigabitEthernet0/0
L        192.168.6.251/32 is directly connected, GigabitEthernet0/0
      192.168.101.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.101.0/24 is directly connected, Serial0/0/0
L        192.168.101.253/32 is directly connected, Serial0/0/0

Router 2 at sister branch:
sh ip int brief:
Interface                  IP-Address      OK? Method Status                Protocol
GigabitEthernet0/0         192.168.7.250   YES NVRAM  up                    up

GigabitEthernet0/1         unassigned      YES NVRAM  administratively down down

Serial0/0/0                192.168.101.254 YES NVRAM  up                    up

sh ip route:
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, + - replicated route

Gateway of last resort is 192.168.101.253 to network 0.0.0.0

S*    0.0.0.0/0 [1/0] via 192.168.101.253
      192.168.7.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.7.0/24 is directly connected, GigabitEthernet0/0
L        192.168.7.250/32 is directly connected, GigabitEthernet0/0
      192.168.101.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.101.0/24 is directly connected, Serial0/0/0
L        192.168.101.254/32 is directly connected, Serial0/0/0
I have gone over the config serveral times. Comparing it to the old cisco routers we have currently using until the issue is resolved. An intern thinks it has to do with the IP address being variably subnetted, with 2 subnets and 2 maks. The config on the old routers only say directly connected like some of the IP's in the information I have posted. He knows it has to do something with the routing config if each router can ping/communicate with each other but a machine on one router end cannot ping a machine on the other router end. Any suggestions are greatly appreciated.

To answer ikalmar'sfirst reply, we had set the two default routes as it was the same set up on the previous routers and they are working just fine. We have not attempted redist static yet.
ASKER CERTIFIED SOLUTION
Avatar of Istvan Kalmar
Istvan Kalmar
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There was another hop that is owned and managed by AT&T (gateway router).  We had to contact AT&T MIS support to have them add a route to the extended network.
This question has been classified as abandoned and is being closed as part of the Cleanup Program. See my comment at the end of the question for more details.