# [SOLVED] HP Procurve RIP routing query



## TheWiz (May 30, 2008)

Hi. I'm new to Techsupportforum and hope there are some HP savvy people out there who can help me. I am a Cisco specialist so therefore am struggling a little with this HP problem. I will list the scenario and then the issue and hope someone can help out.

Core switch is a HP 5304XL. It talks to a firewall via OSPF for Internet access on one vlan, and to another HP switch for internal Global routes via OSPF on another. Users are on a third vlan. I recently added a remote office to the network using two (2) wireless links (the remote office is accross the road) and placed both links into the user vlan to bridge this LAN to the new office (bridging and using STP to take care of the loop). The two links connect to a HP procurve 3500YL switch with a dozen users on it. This all worked fine but as there are VoIP phones in use in the remote office, collisions in the wireless link was a potential issue.

I thus constructed a new design where the links were made into layer 3 links on new vlans in the core switch and the remote switch. I have configured RIP on these two switches for both of these vlans to get routing information to the remote office. The core switch is redistributing its configured static route for 0.0.0.0 to the remote switch via RIP. I configured opposing interfaces with differing RIP metrics to preference traffic flows. Link one at core has metric 5 added to learned routes and link two is default metric 1. Link one at remote has default metric 1 and link two has metric 5 added to learned routes. Thus, traffic flows should be from core to remote site via link two and return via link one. A psuedo full duplex set up that prevents collisions except if one link fails and all traffic flows over one link again.

This is where I run into my problem. The remote switch see's link one as the best default route (advertised by RIP from the core switch) and thus traffic flows that way which is as expected. The core switch sees the remote LAN as being via link 2 (show ip route) BUT when you do a traceroute from a user in the core site, traffic flows through the link one neighbour (shows link one IP as a hop). If I traceroute from the core switch I go through link two as expected. Why is this and how do I get the traffic from a user/server to flow to the remote office via the installed route using link two???

I either know less about RIP routing than I thought - or - the HP's do something I can't see and I don't have enough experience with them to see it. Many thanks in advanbce for any help offered. I have trolled HP website and perused many manuals but no luck. I am happy to post a simple network diagram if needed or some relevant config or show commands.

Thanks,

TheWiz


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## makemorebeer (May 20, 2008)

*Re: HP Procurve RIP routing query*

well i'm sure you've already tried using the show ip rip command ont he HP's and found that the data there is hardly helpful. after you responded to my post our problems seem very similar. shortcoming's of RIP, and switch capabilities. your problem however may have a much easier answer. the remote site's configured with a different subnet than the main office? if this is the case you can do what i'm doing and convert to layer three via the use of a a router both at main site and remote site and run a dual connection via your wireless links that way. in this case you'd have all the benefits of full IP routing and metrics. of course i understand this may not be an option, but it may help to solve your issue. it sounds almost as if your routes are load balancing though, which i'm not sure if the HP's can do this or not but I know cisco's can. For example i've got dual GRE tunnels, and a T1 running from my main site to a remotes site in another state, and thats what my traces look like. it'll give me all three addresses and then depending on network load it'll only give a transfer time on one of them. i think both of our biggest problems is it seems the HP's are not running full features versions of the RIP protocol, reference inability to enter enter specific networks into the HP's, or entering neighbors manually.


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## TheWiz (May 30, 2008)

*Re: HP Procurve RIP routing query*

Many thanks to a guy called Matt Hobbs from the HP forums who seems to have come up with the answer.

"I'm wondering if this being caused by a software bug on the 3500... With the current version of software on the 3500, there is an issue with ICMP TTL expired messages being sent with the SA of the interface that the messages leaves from, rather than the interface that received the expired packet. This will cause your traceroutes to give you misleading information but other traffic should be taking the correct path.

If you contact ProCurve support you can request K.13.16 which should resolve that. 

Otherwise, can you verify that traffic is taking the right path by blasting some traffic out and checking your port counters?"

I tried the advice above and traffic was indeed following the correct path so it seems I am suffering from misleading traceroute information caused by the 3500 bug. An image upgrade is planned to resolve this. Hope this may help others.


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