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Bartek
Asked: 2009-11-18 09:37:53 +0800 CST

iptables -L pretty slow. Is this normal?

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Quick question but Gooling has not revealed an answer. When I do iptables -L, it seems to lag on displaying items in where I have limited the source to internal ips 192.168.0.0/24

The whole listing takes about 30 seconds to display.

I just want to know: Does this affect the speed of my incoming connections or is this simply a side effect of having all these ranges within my iptables rules?

Thanks!

linux

3 Answers

  1. Best Answer

    Include the -n option so it doesn't try to use DNS to resolve names for every ip address, network and port. Then it will be fast.

    • 83

  2. For me it was slow and also I was getting this error 

    sudo: unable to resolve host selleraz-proxy-service: Resource temporarily unavailable

    I add 

    127.0.0.1   machine-hostname

    to /etc/hosts It worked so well like a charm :)

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  3. I've personally seen this happen on a server that was configured for LDAP authentication, but could not reach the LDAP server (this was SLED 10). In my case, "netstat -a" and "iptables -L" were both exhibiting the same behavior you describe. An "strace" of the netstat showed it hanging on a connection to port 636 (LDAP-Secure). Turning off the LDAP (which, for me, was not needed on this platform) fixed the problem.

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