From: Peter A. van Oene (vantech@xxxxxxxxxxxx)
Date: Sun Apr 23 2000 - 12:37:26 GMT-3
I agree with the no synch rule allowing an IBGP router to post a number of
routes which it itself cannot validate to its table, however I have to
differ on the point of next-hop-self addressing the same concern. Synch or
no synch, a router I or E will not post a route to any table unless it has
a route to the next hop address. In this case, i believe the router is
fine with the next hop address in all cases, however it cannot verify with
an IGP the EGP routes.
(standard caveat of "of course, i could be mistaken" applies here :)
*********** REPLY SEPARATOR ***********
On 4/23/00 at 2:23 AM Stanley Seow wrote:
>Yes, you are on the correct track...
>
>No Sync will dump the bgp table into your routing table ( assuming all
>your IBGP are fully mesh ).
>
>Another way is to put next-hop-self on the first router neighbour pointing
>to your IBGP router so that it will know how to reach the next hop
address.
>
>
>Stanley
>
>> -----Original Message-----
>> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
>> EHess
>> Sent: Saturday, April 22, 2000 9:17 PM
>> To: ccielab@groupstudy.com
>> Subject: BGP brain block
>>
>>
>> I am having a brain block with BGP when using IBGP in an AS. The
situation
>> is this: I have 2 routers in the same AS connected by a token ring
network
>> as IBGP peers. The first router is also an EBGP router and seems
>> to show all
>> routes properly in its routing table.
>>
>> The second router (IBGP peer) shows all the routes in its BGP
>> table but not
>> in the main routing table. It is my understanding that the routes
>> should be
>> displayed in the main routing table table because the second router has
a
>> route to the next-hop-address. The only way I can get this to work is by
>> using the "no sync" command.
>>
>> Question: Am I correct in my thinking or can someone straighten me out
on
>> this matter. I am attaching copies of the main routing table and the BGP
>> table.
>>
>> Thanks for any help,
>> Edward Hess
>>
>> Gateway of last resort is not set
>>
>> R 172.18.0.0/16 [120/1] via 180.100.1.1, 00:00:02, TokenRing0
>> 11.0.0.0/24 is subnetted, 1 subnets
>> B 11.1.1.0 [20/0] via 180.100.2.2, 00:00:03
>> 180.100.0.0/24 is subnetted, 2 subnets
>> C 180.100.1.0 is directly connected, TokenRing0
>> C 180.100.2.0 is directly connec
>>
>>
>> happy#ping 172.18.105.1
>>
>> Type escape sequence to abort.
>> Sending 5, 100-byte ICMP Echos to 172.18.105.1, timeout is 2 seconds:
>> !!!!!
>> Success rate is 100 percent (5/5), round-trip min/avg/max = 40/41/44 ms
>> happy#sh ip rou 172.18.105.1
>> Routing entry for 172.18.0.0/16
>> Known via "rip", distance 120, metric 1
>> Redistributing via rip
>> Advertised by rip (self originated)
>> Last update from 180.100.1.1 on TokenRing0, 00:00:01 ago
>> Routing Descriptor Blocks:
>> * 180.100.1.1, from 180.100.1.1, 00:00:01 ago, via TokenRing0
>> Route metric is 1, traffic share count is 1
>>
>> happy#sh ip bgp
>> BGP table version is 20, local router ID is 180.100.2.1
>> Status codes: s suppressed, d damped, h history, * valid, > best, i -
>> internal
>> Origin codes: i - IGP, e - EGP, ? - incomplete
>>
>> Network Next Hop Metric LocPrf Weight Path
>> *>i10.1.1.0/24 180.100.1.1 0 100 0 i
>> *> 11.1.1.0/24 180.100.2.2 0 0 400 i
>> *>i160.1.1.0/24 172.18.105.1 100 0 200 100 i
>> *>i161.1.1.0/24 172.18.105.1 100 0 200 100 i
>> *>i163.100.0.0 172.18.105.1 100 0 200 100 i
>> *>i171.17.1.0/24 172.18.105.1 0 100 0 200 i
>> *>i171.18.1.0/24 172.18.105.1 0 100 0 200 i
>> *>i172.18.0.0 172.18.105.1 0 100 0 200 i
>> *>i172.18.104.0/24 172.18.105.1 100 0 200 100 i
>> *>i172.18.105.0/24 180.100.1.1 0 100 0 i
>> *> 180.100.0.0 0.0.0.0 0 32768 i
>> * i 180.100.1.1 0 100 0 i
>> *> 180.100.1.0/24 0.0.0.0 0 32768 i
>> *> 180.100.2.0/24 180.100.2.2
>>
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