Bug 55254 - Bad: iptables masquerading after network restart has a problem
Summary: Bad: iptables masquerading after network restart has a problem
Alias: None
Product: Red Hat Linux
Classification: Retired
Component: initscripts
Version: 7.2
Hardware: i586
OS: Linux
Target Milestone: ---
Assignee: Bill Nottingham
QA Contact:
Depends On:
TreeView+ depends on / blocked
Reported: 2001-10-28 12:49 UTC by Tanel
Modified: 2014-03-17 02:24 UTC (History)
3 users (show)

Clone Of:
Last Closed: 2003-02-06 14:13:41 UTC

Attachments (Terms of Use)

Description Tanel 2001-10-28 12:49:15 UTC
From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)

Description of problem:
after I have done network restart (/etc/init.d/network restart), iptables 
will not masquerade any more connections to the same public IP Network, 
which itself belongs to. Connections to all other IP-s will still be 
masqueraded properly. 

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1.Redhat 7.2 has 2IP-s, for example, and alias
1.iptables -t nat -D POSTROUTING -s -j MASQUERADE
2./etc/init.d/network restart
3.ping or telnet or whatever from client ( to 
(_same_ subnetwork which Redhat 7.2 belongs to)

Actual Results:  Packets coming from will not be masqueraded 
as coming from but as Destination host receives packets from, which were originally 
created from

Expected Results:  packets coming from should have been 
masqueraded as and routed to destination IP (

Additional info:

Redhat 7.2, kernel 2.4.9-7.

Comment 1 Bernhard Rosenkraenzer 2001-10-30 11:54:09 UTC
Guess the ifup script should run iptables on the new device...

Comment 2 Tanel 2001-10-30 16:19:20 UTC
Flushing all iptables chains, incl. POSTROUTING and reinserting rule
iptables -t nat -A POSTROUTING -s -j MASQUERADE will not solve 
the problem, as well as killing and reloading masquerade and nat modules.

Comment 3 Oliver Schulze L. 2003-02-06 14:03:28 UTC
The reporter does not runs the correct commands.
This should be run to resolve the issue:
1.iptables -t nat -D POSTROUTING -s -j MASQUERADE
2. service iptables save
3. service network restart
4. service iptables restart
5. ping or telnet or whatever from client ( to 

Please close as NOTABUG

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