[Xorp-users] Fwd: Re: Route Redist between RIP and OSPF - working?

[David Davidson]

Hey Steve:

There was one thing I forgot to mention: my connected routes (exported 
VIA policy) seemed to work okay on the OSPF side; so I should back-pedal 
a little and say that my results weren't >exactly< like yours because my 
connected routes were injected into OSPF, just the RIP routes were not. 
Hence, I am going to explain what I think you might try out below. 
Please read on...

I tested this with 5 routers instead of 3. I added a router xorp4, 
connected to another interface on xorp3 using 10.0.0.1/24 on xorp3 and 
10.0.0.2/24 on this xorp4, also using RIP so I can see how the RIP 
routes from further away would behave. Likewise, I added a xorp5 router 
on the OSPF side, connected to xorp1 using a 172.16.1.1/24 on xorp1 and 
172.16.1.2/24 on xorp5, here again so I could see how the ospf routes 
from further away behaved.

For better clarity, I have attached a text document which documents the 
configuration for each of the 5 routers. The core router, xorp2, is 
where I have tried to implement the RIP and OSPF policies.

Back to the issue, so I think this might have something to do with the 
way the XORP developers decided to implement the RIP protocol, and/or 
maybe just the RIP export policies. Some network vendors are different 
in the way they implement export policies, and also what gets exported 
by default (if anything at all). For example, I believe that at least 
one network vendor's default export policy for RIP, whose syntax is very 
similar to that of XORP's, for RIP, is not to export ANYTHING at all, by 
default (RIP export policy: "reject everything" by default, per at least 
one official document I have here). Perhaps the XORP developers also 
intended this to be the same way on the RIP implementation for XORP, or 
its RIP export policies under XORP.

Please let me know if this works: Go ahead and assign a "connected" 
policy export on your xorp3 router (40.2). For example, I added this to 
my xorp3 router in this particular lab:

configure exclusive
set policy policy-statement RIPCON term 1 from protocol connected
set policy policy-statement RIPCON term 1 then accept
set protocols rip export RIPCON
commit

What do you think? Did that do the trick? This worked for me. After I 
added that policy to xorp3, the OSPF router on the left (xorp1) learns 
about the RIP routes and vice-versa (my rip routers on the right, xorp3, 
learn about the OSPF routes, but this was already happening before anyway).

If that worked, then also, consider, if you had other routers upstream 
RIP routers from xorp3 (like here in the lab I did, I have a xorp5 RIP 
router connected to xorp3, like I mentioned above) then you would add 
RIP also and then use a policy like this one instead:

configure exclusive
set policy policy-statement RIPCON-and-RIP term 1 from protocol connected
set policy policy-statement RIPCON-and-RIP term 1 then accept
set policy policy-statement RIPCON-and-RIP term 2 from protocol rip
set policy policy-statement RIPCON-and-RIP term 2 then accept
set policy policy-statement RIPCON-and-RIP term 3 then reject
set protocols rip export RIPCON-and-RIP
commit


These worked for me. If they work for you, then my bet is - this 
implementation closely follows the RIP export policies like some of the 
other network vendors out there that have similarly implemented RIP 
export policies and defaults for export policies (i.e. by default, 
reject all on RIP export policies).

David


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