We have two datacenters same logical LAN.
Two ISP routers and two WAE 674 and using WCCP "egress-method negotiated-return intercept-method wccp"
See attached file.
The problem is when one of the "line" WAN interface goes down, some of the network are not reach from the LAN side and some are.
We are using BGP as routing protocol in the ISP routers.
Any suggestion for the problem?
You can open a TAC case and they can assist you to retain confidentiality.
Further, about the static routes , BGP and RIP, I am not sure if I am the right person to answer that. You probably want to put this across Routing forum to get a more specific answer.
From WCCP perspective, WCCP will only change its status if the WCCP goes down by means of non-rechanble router / CE. Otherwise, if the WAN interface goes down, WCCP may still remain alive depending on your configuration because all WCCP cares is redirect traffic to CE and receive it back from CE and then forward it to gateway. If the gateway is not reachable, connectivity breaks but not WCCP. So, you want to make sure to probably add a static route in router to forward the traffic to backup gateway if the WAN link goes down.
Hope this helps.
PS: Please mark this as Answered, if this resolves your issue.
What is suspect here is WCCP.
When you configure, it allocates buckets if you are using hash assignment. If you are using Mask, it calculates mask depending on your destination / source ip address.
Now, what I understand is - if WAN goes down, some networks are not reachable.
When LAN goes down, WCCP goes down and everything starts running smooth.
1. What happens if LAN goes down but WAN remains up? Does WCCP remain active / usable state?
2. When WAN goes down and LAN remains up, your WCCP is still UP and hence, it continues to forward packets out of same WAN interface but because that interface is down, packets ultimately die / gets blackholed.
3. Another speculation is: Asymmetric routing. When WAN is down but LAN is up, you are forwarding soem traffic out of LAN but as WAN goes down, the return packets then come up on different interface and creates asymmetric routing.
To narrow down this problem, please capture following interface during three stages:
1. WAN - Down, LAN-UP, is router ID reachable ???
2. WAN-UP, LAN- - Down, is router ID reachable ???
3. WAN Down, LAN Down, is router ID reachable ???
CLI logs to capture:
2. show ip wccp
3. show ip wccp interface detail
4. show ip wccp service
5. show ip wccp detail
6. show ip wccp internal (*)
7. show running-config
8. show ip wccp <61 / 62> hash
9. sh wccp mask tcp-promis
10. sh tech
Further, as you are using GRE encapsulation for WCCP redirection, the router uses the router ID IP address as its source IP address. The router ID IP address is the highest loopback address on the router, or if the loopback interface is not configured, the router ID IP address is the highest address of the physical interfaces. The router ID IP address is used as the source address for packets redirected from the router to the Cisco WAE, and as a result it is also used as the destination address for traffic from the Cisco WAE to the router, Therefore, you must be sure that a route exists from the Cisco WAE to the router. This is done by configuring a static route on the Cisco WAE to the router ID IP address. The router ID can be identified with the command show wccp routers on the Cisco WAE.
As in your case, you have multiple routers, a static route should be added to each of these router's router ID. The command to configure such static routes is: