09-19-2005 09:05 AM - edited 03-03-2019 10:32 AM
We are having intermittent problems across our WAN, and have been unable to determine what is causing it.
- There are two networks involved; Net A - 10.1.3.0/24 and Net B - 10.1.2.0/24 and 200.200.29.0/24.
- There are two Cisco 1720 routers which route traffic over a T1 between the two networks.
- Net A's 1720 is NI=10.1.3.1 SI=192.168.255.2 (we'll call it Router A)
- Net B's 1720 is NI=10.1.2.6 SI=192.168.255.1 (we'll call it Router B)
- Net B has another router (200.200.29.5 and 10.1.2.5) which allows both subnets (10.1.2.0/24 and 200.200.29.0/24) on the same wire. (We'll call it router C)
- Router C is the default gateway for all devices on Net B.
- Router A is the default router for all devices on Net A
What is happening is when a device on Net A tries to ping a device on Net B's 10.1.2.0/24 network, it gets intermittent results. Sometimes it can ping a specific device, while sometimes it cannot ping that same device. I have noticed that once they are able to ping a 10.1.2.0 IP address, they seem to be able to do so for a while. However, if I log off of that machine and I come back later in the day, it wont be able to ping that same IP address. The wierd part is that they never have a problem pinging one of Net B's 200.200.29.0 addresses.
Here are the routing tables on each of the routers:
Router A
router eigrp 12
network 10.0.0.0
eigrp log-neighbor-changes
!
ip classless
ip route 0.0.0.0 0.0.0.0 192.168.255.1
ip route 10.1.2.0 255.255.255.0 192.168.255.1
ip route 200.200.29.0 255.255.255.0 192.168.255.1
Router B
router eigrp 12
network 10.0.0.0
no eigrp log-neighbor
!
ip classless
ip route 0.0.0.0 0.0.0.0 10.1.2.5
ip route 10.1.3.0 255.255.255.0 192.168.255.2
ip route 200.200.29.0 255.255.255.0 10.1.2.5
Router C (non-cisco)
ip route 10.1.3.0 255.255.255.0 10.1.2.6
Any input would be helpful. I have attached a connectivity drawing that will hopefully help.
09-19-2005 09:48 AM
The first thing that I would try is to turn off auto-summary (no auto-summary in the router eigrp 12 section on both routers). The default is summary, so both routers should have a directly connected route to 10.0.0.0/8. However, the static routes should be taking precedence over this route. Take a snapshot of the routing tables before and after you turn off auto-summary.
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