Greetings; I'm using Debian GNU/Linux sarge-sid; working with iptables configured as follows: (iptables -L)

Chain INPUT (policy DROP)
target prot opt source destination
ACCEPT tcp -- anywhere anywhere tcp spt:1863
ACCEPT tcp -- anywhere anywhere tcp multiport ports 10000
ACCEPT tcp -- anywhere anywhere tcp multiport ports ssh
ACCEPT tcp -- anywhere anywhere tcp multiport ports www state RELATED,ESTABLISHED
ACCEPT udp -- anywhere anywhere multiport ports domain udp
ACCEPT tcp -- anywhere anywhere tcp multiport ports domain
ACCEPT tcp -- anywhere anywhere tcp multiport ports smtp state ESTABLISHED
ACCEPT tcp -- anywhere anywhere tcp multiport ports pop3
ACCEPT icmp -- anywhere anywhere icmp echo-reply
ACCEPT tcp -- anywhere anywhere tcp spt:28900

Chain FORWARD (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere anywhere

Chain OUTPUT (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere anywhere
ACCEPT icmp -- anywhere anywhere

Even with ICMP traffic completely available I can't ping myself nor other people can, too. I have allowed 28900 TCP port access because it's used by Tactical Ops game but it also does a huge server ping. The game is about unplayable without that. Not to tell that I can't now my latency now! Please, I would appreciate any help.

Thank you very much

firt of all... your output policy is ACCEPT... is this delibrate ?
if so, your output rules are pointless, there not needed.

next, you are blocking icmp type 8 packets,
which is why you cant ping yourself

/sbin/iptables -A INPUT -p icmp --icmp-type echo-request -j ACCEPT
will fix that

agh, yor frewall rules are messy and hard to read.
maybe clean them up a little, i see quite a few redundant rules,
and rules which could be merged together.

Thank you very much, I've allowed echo-request ICMP packets and now everything is working fine.

Yes, they are really messy I don't get around with firewalls so it's kind of a disaster, but now I'm working on it, I've merged some rules, and so on.

I've also changed output default policy to DROP and made new output rules for what I want.

Thank you ver much,