From jeremyp@gsmx07.alcatel.com.au  Fri Nov  3 17:50:09 2000
Return-Path: <jeremyp@gsmx07.alcatel.com.au>
Received: from alcanet.com.au (unknown [203.62.196.10])
	by hub.freebsd.org (Postfix) with SMTP id 4149D37B4C5
	for <FreeBSD-gnats-submit@FreeBSD.ORG>; Fri,  3 Nov 2000 17:50:07 -0800 (PST)
Received: by border.alcanet.com.au id <115201>; Sat, 4 Nov 2000 13:49:26 +1100
Message-Id: <00Nov4.134926est.115201@border.alcanet.com.au>
Date: Sat, 04 Nov 2000 12:27:20 +1100 (EST)
From: peter.jeremy@alcatel.com.au
Sender: jeremyp@gsmx07.alcatel.com.au
Reply-To: peter.jeremy@alcatel.com.au
To: FreeBSD-gnats-submit@FreeBSD.ORG
Subject: NFS can't handle asymmetric server routing
X-Send-Pr-Version: 3.2

>Number:         22596
>Category:       kern
>Synopsis:       NFS can't handle asymmetric server routing
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          closed
>Quarter:        
>Keywords:       
>Date-Required:  
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Nov 03 18:00:02 PST 2000
>Closed-Date:    Fri Nov 3 21:43:05 PST 2000
>Last-Modified:  Fri Nov 03 21:43:42 PST 2000
>Originator:     Peter Jeremy
>Release:        FreeBSD 5.0-CURRENT i386
>Organization:
Alcatel Australia Limited
>Environment:

	Client: FreeBSD 5-CURRENT PRE_SMPNG
	Server: FreeBSD 5-CURRENT late August 2000

>Description:

	Given the following network configuration.  If the server
	routes to the client via router-3 and the client attempts
	to NFS mount a filesystem via server-2, the mount will
	block indefinitely.

	              +------+  -2  +------+
	+------+  -1  |      |------|      |
	|client|------|router|      |server|
	+------+      |      |------|      |
	              +------+  -3  +------+

	For example "mount server-2:/cdrom /cdrom" produces the
	following network packets:
	
12:16:32.119294 client-1.976 > server-2.111:  udp 56
12:16:32.303056 server-2.111 > client-1.976:  udp 28
12:16:32.305913 client-1.975 > server-2.111:  udp 56
12:16:32.481473 server-3.111 > client-1.975:  udp 28
12:16:32.488073 client-1.855771785 > server-2.2049: 40 null
12:16:32.652983 server-2.2049 > client-1.855771785: reply ok 24 null
12:16:32.656422 client-1.973 > server-2.111:  udp 56
12:16:32.821607 server-3.111 > client-1.973:  udp 28
12:16:32.831160 client-1.972 > server-2.1017:  udp 124
12:16:33.111041 server-2.1017 > client-1.972:  udp 68
12:16:33.180257 client-1.1718190197 > server-2.2049: 124 access fh 117,2/3 003f
12:16:33.421336 server-3.2049 > client-1.1718190197: reply ok 120 proc-135571692
12:16:33.422329 client-1 > server-3: icmp: client-1 udp port 971 unreachable

	The last 3 packets repeat indefinitely (with exponential backoff).

	When I change the routing on the server so packets for client-1
	go via server-2 instead, it recovers and completes the mount:

12:17:44.046144 client-1.1718190197 > server-2.2049: 124 access fh 117,2/3 003f
12:17:44.247190 server-2.2049 > client-1.1718190197: reply ok 120 access c 0023

>How-To-Repeat:

	Set up network and issue mount command as per above.

>Fix:

	Unknown.  The client is correct to reject the packets from an
	(unknown) server.  The server should be using a source address
	that matches the address that the client requested to mount.



>Release-Note:
>Audit-Trail:
State-Changed-From-To: open->closed 
State-Changed-By: dougb 
State-Changed-When: Fri Nov 3 21:43:05 PST 2000 
State-Changed-Why:  
Duplicate of 22594, originator request 

http://www.freebsd.org/cgi/query-pr.cgi?pr=22596 
>Unformatted:
