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by afari

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i am setting a linux box as a squid cache server and a firewall. I used linuxconf to do the configuration.

under firewall, i enabled all the services except
1. forwarding rules and
2. outputting rules

after everything, i connected the linux box to my network to test it.

i pinged and got this message:

PING: SENDTO: OPERATION NOT PERMITTED
PING: WROTE 192.168.1.238 64 CHARS, RET=-1

THE IP NUMBER IS FOR MY LINUX BOX.
can somebody help me.

5 replies

by joematus

Could be a routing issue or it could be your firewall is blocking your pings. Check your routing table to see if you have a route to your destination (netstat -rn). Assuming you're using ipchains, shutdown your firewall to see if it's doing the blocking (/etc/init.d/ipchains stop). It also could be the non-routable ip addresses you're using but I don't know your network setup.

by r.rieth

Hi,
1. check your firewall rules for lines dening icmp
packets send to or coming from the ethernet cards of your linux box. if you found some, delete these
lines.

2. check settings in /proc/sys/net/ipv4/icmp_echo_ignore_all. (cat /proc/... works). You should get "1" as a result, e.g. all icmp packets are ignored by your firewall box (this is a default setting in most firewall scripts i've seen)
Try echo "0" > /proc/sys/net/ipv4/icmp_echo_ignore_all.

now you can ping from/to your linux box.

good luck and have fun

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