From: Gopal@xxxxxxxxxxxxxxxxxx
Date: Sat Feb 10 2001 - 22:45:29 GMT-3
once you know the neighbor ip,
1)make a neighbor with a random AS number
2)deb ip bgp-- THIS GIVES THE RIGHT AS#.
HOPE THIS HELPS,
GOPAL
2d01h: BGP: 202.1.1.1 OPEN has ROUTE-REFRESH capability(old) for all
address-fam
ilies
2d01h: BGP: 202.1.1.1 bad OPEN, remote AS is 1, expected 3 ----------->HERE
IS THE RIGHT AS#
2d01h: BGP: 202.1.1.1 went from OpenSent to Closing
2d01h: %BGP-3-NOTIFICATION: sent to neighbor 202.1.1.1 2/2 (peer in wrong
AS) 2
bytes 0001
2d01h: BGP: 202.1.1.1 local error close, erroneous BGP update received
2d01h: BGP: 202.1.1.1 send message type 3, length (incl. header) 23
2d01h: BGP: 202.1.1.1 went from Closing to Idle
2d01h: BGP: 202.1.1.1 closingu all
All possible debugging has been turned off
s2-r2-2500-2501C#
2d01h: %BGP-3-NOTIFICATION: sent to neighbor 202.1.1.1 2/2 (peer in wrong
AS) 2
bytes 0001
-----Original Message-----
From: Manish Rajdev <ccieapr@yahoo.com>
To: Gopala Naganab <netlanceconsulting@yahoo.com>
Cc: ccielab@groupstudy.com <ccielab@groupstudy.com>
Date: Saturday, February 10, 2001 6:06 PM
Subject: Re: ct: Re: BGP
>Hi Gopala,
>
>How do u find the AS no. I got the IP part, but if we
>need to put the AS no in the neighbor statment, then
>How can we find that out ?
>
>THanks In advance
>Manish
>--- Gopala Naganab <netlanceconsulting@yahoo.com>
>wrote:
>> sho ip pack detail ----->gave me the following.
>>
>> s2-r2-2500-2501C#u all
>> All possible debugging has been turned off
>> s2-r2-2500-2501C#deb ip pa det------------>DEBUG
>> IP packet debugging is on (detailed)
>> s2-r2-2500-2501C#
>> 21:28:54: IP: s=142.108.10.8 (Ethernet0),
>> d=142.108.10.7, len 44, rcvd 0------------> LOOK FOR
>> S= ADDR
>> 21:28:54: TCP src=11200, dst=179,
>> seq=2225043935,
>> ack=0, win=16384 SYN-------------->LOOK FOR DST=179
>> TCP PORT FOR BGP
>> 21:28:54: IP: s=142.108.10.7 (local), d=142.108.10.8
>> (Ethernet0), len 40, sending
>> 21:28:54: TCP src=179, dst=11200, seq=0,
>> ack=2225043936, win=0 ACK RST
>>
>> SOURCE IP IS THE ONE YOU SHD USE IN NEIGHBOR CMND.
>> DEST IP ADDR IS SUPPOSED TO BE 'UPDATE SOURCE' IN
>> THE
>> NEIGHBOR STATEMENT..
>>
>> CHEERS,
>> GOPAL
>>
>>
>>
>> *****************
>> If I knew the IP address, I would attempt to peer
>> with
>> it and then sniff
>> the reply packets for the remote ASN. I don't know
>> if
>> that would work but
>> I would TRY it. Also...there may are arin records
>> on
>> who owns which
>> address space and you might be able to match THAT
>> with
>> an ASN as well.
>>
>> Not knowing the IP address...you'd have to make a
>> few
>> assumptions about
>> the remote router's medium and work with that. If
>> it's ethernet...ping
>> the subnet broadcast to see if any routers return an
>> icmp reply. If it's
>> frame relay, try inverse arp...if it's ATM...you're
>> on
>> your own. =-)
>>
>> Also...look for the remote router trying to
>> establish
>> a session with your
>> router, that would most definitely have the remote
>> ASN
>> in the packet.
>>
>>
>> BUT...without knowledge of the IP and of the ASN's
>> involved...you really
>> SHOULDN'T be trying to establish a peering session.
>> Unless it's for lab
>> purposes. And I CAN tell you, that they do NOT
>> withhold information from
>> you in the lab that isn't TOO difficult to find out
>> for yourself. =-)
>>
>>
>> On Mon, 5 Feb 2001, Devender Singh wrote:
>>
>> > How would you know AS number of the remote AS,
>> or/and also ip address. Given
>> > that you cannot have any kind of access into the
>> router and cdp is disabled.
>> >
>> > I donnot know. Any suggestions.
>> >
>> > Devender Singh
>> > BE(Hons), CCNP
>> > IP Solution Specialist
>>
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:28:45 GMT-3