RE: Telnet on port 179

From: Scott Morris (swm@emanon.com)
Date: Wed Oct 22 2008 - 23:22:55 ARST


I was pondering that after I hit send. :)
 
The original thought was that bgp neighbors are set based on explicit
update-sources. So if your other router was expecting the session to come
from the loopback instead of the directly attached router link then it may
not peer up.
 
On the flip side, I'm pretty sure that's a BGP check, not a TCP filtering of
any sort, so you should still see the session start there regardless.
 
But really, it seemed like a good idea at the time! (grin)
 
Scott

  _____

From: Mahesh Shivaswamy [mailto:maheshs.cisco@gmail.com]
Sent: Wednesday, October 22, 2008 9:01 PM
To: swm@emanon.com
Cc: Scott M Vermillion; Cisco certification
Subject: Re: Telnet on port 179

The subnet b/w R4 & SW1 is 154.1.47.0/24, When I telnet from R4-> SW1 it
will use the outgoing interface IP 154.1.47.4, wondering why will I need to
worry abt update-source address here ?

rgds
Mahesh

On Wed, Oct 22, 2008 at 7:30 PM, Scott Morris <swm@emanon.com> wrote:

And are you using the same update-source address?

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of

Scott M Vermillion
Sent: Wednesday, October 22, 2008 8:04 PM
To: 'Mahesh Shivaswamy'; 'Cisco certification'
Subject: RE: Telnet on port 179

Do you have an appropriate neighbor statement?

SW1#telnet 1.0.0.2 179
Trying 1.0.0.2, 179 ...
% Connection refused by remote host

SW2(config)#ip routing
SW2(config)#router bgp 100

SW1#telnet 1.0.0.2 179
Trying 1.0.0.2, 179 ...
% Connection refused by remote host

SW2(config-router)#neigh 1.0.0.1 remote-as 100

SW1#telnet 1.0.0.2 179
Trying 1.0.0.2, 179 ... Open

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Mahesh Shivaswamy
Sent: Wednesday, October 22, 2008 5:55 PM
To: Cisco certification
Subject: Telnet on port 179

Hi,

When I telnet on port 23 between R4 & SW1 its fine, but when I telnet on
port 179 I get a connection refuse msg, there is no access list on SW1.

R4#telnet 154.1.47.7
Trying 154.1.47.7 ... Open

User Access Verification

Password:

R4#telnet 154.1.47.7 179
Trying 154.1.47.7, 179 ...
% Connection refused by remote host

SW1#
1d11h: tcp0: I LISTEN 154.1.47.4:18645 154.1.47.7:179 seq 2990396955
       OPTS 4 SYN WIN 4128
1d11h: TCP: sent RST to 154.1.47.4:18645 from 154.1.47.7:179

SW1#sh run int vlan 47
Building configuration...

Current configuration : 61 bytes
!
interface Vlan47
 ip address 154.1.47.7 255.255.255.0
end

Any suggestion what is the issue, this is the only way I can test, any
suggestion ?

rgds
Mahesh

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