Date: Wed, 28 Nov 2001 14:47:54 -0000 From: "Tariq Rashid" <tariq@inty.net> To: <freebsd-net@freebsd.org> Subject: solved : ip change ? not according to tcpdump. Message-ID: <MPENKFCCIIDAJKJJOLBHKEPOCCAA.tariq@inty.net> In-Reply-To: <MPENKFCCIIDAJKJJOLBHAEPOCCAA.tariq@inty.net>
next in thread | previous in thread | raw e-mail | index | archive | help
apologies - natd was running on the interfaces which causes the effects.
well - i didn't know that natd didn't respond to ip address changes...
t
-----Original Message-----
From: owner-freebsd-net@FreeBSD.ORG
[mailto:owner-freebsd-net@FreeBSD.ORG]On Behalf Of Tariq Rashid
Sent: 28 November 2001 14:18
To: freebsd-net@freebsd.org
Subject: ip change ? not according to tcpdump.
his post is about an IP address not being reflected "on the wire":
Two freebsd 4.4-release boxes are connected over ethernet via a hub (using
nics at 10Mbs).
The hub is simple in that it doesn't do anything fancy like arp proxying or
caching....
[ A ] ------- ------- [ B ]
| |
[ hub ]
I change the ip address on A as follows:
* ifconfig fxp0 down
* ifconfig 192.168.1.33 (it was 192.168.1.3)
* ifconfig fxp0 up (for good measure!)
now, on A:
* pinging 192.168.1.33 works
* pinging 192.168.1.3 does not -- all good so far
now pinging machine B (ping 192.168.1.1) WORKS :
13:13:48.460568 192.168.1.3 > 192.168.1.1: icmp: echo request
13:13:48.460862 192.168.1.1 > 192.168.1.3: icmp: echo reply
BUT a tcpdump shows pings coming from the old 192.168.1.3 address.
This is a problem as other applications like IKE daemons (isakmpd ported
from openbsd) wants to respond to
the old 192.168.1.3 which isn't there... causing arp requests...
icmp-redirects....
13:13:00.297762 192.168.1.1 > 192.168.1.3: ESP(spi=0x70214267,seq=0x51)
13:13:00.298396 arp who-has 192.168.1.3 tell 192.168.1.33
13:13:00.298468 192.168.1.33 > 192.168.1.1: icmp: redirect 192.168.1.3 to
host 192.168.1.3
Necxt, I tried doing arp -da on both machines... but to no avail: this time
the pings from machine A to B fail with:
13:15:16.914413 192.168.1.3 > 192.168.1.1: icmp: echo request
13:15:17.924035 192.168.1.3 > 192.168.1.1: icmp: echo request
13:15:18.934023 192.168.1.3 > 192.168.1.1: icmp: echo request
13:15:19.944032 192.168.1.3 > 192.168.1.1: icmp: echo request
any ideas anyone?
tariq
-----------------------------------------------
Information in this electronic mail message is confidential
and may be legally privileged. It is intended solely for
the addressee. Access to this message by anyone else is
unauthorised. If you are not the intended recipient any
use, disclosure, copying or distribution of this message is
prohibited and may be unlawful. When addressed to our
customers, any information contained in this message is
subject to Intelligent Network Technology Ltd Terms & Conditions.
-----------------------------------------------
Take part in the intY 2001 Email Usage survey
online at http://www.inty.net/email/survey.html
-----------------------------------------------
intY has automatically scanned this email using Sophos Anti-Virus
(www.inty.net)
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-net" in the body of the message
-----------------------------------------------
Information in this electronic mail message is confidential
and may be legally privileged. It is intended solely for
the addressee. Access to this message by anyone else is
unauthorised. If you are not the intended recipient any
use, disclosure, copying or distribution of this message is
prohibited and may be unlawful. When addressed to our
customers, any information contained in this message is
subject to Intelligent Network Technology Ltd Terms & Conditions.
-----------------------------------------------
Take part in the intY 2001 Email Usage survey
online at http://www.inty.net/email/survey.html
-----------------------------------------------
intY has automatically scanned this email using Sophos Anti-Virus (www.inty.net)
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-net" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?MPENKFCCIIDAJKJJOLBHKEPOCCAA.tariq>