iptables chain name no more than 30 chars?
I can use 31 chars chain name in Debian 6 (iptables 1.4.8), but in Ubuntu 11 (iptables 1.4.10), I can't... Is it possible to let Ubuntu support 30+ chars chain name?
Yes it's possible. You'll have to download the source from netfilter.org or get your distro's soure code. once you've done that make a suitable change and recompile.
Now you have an unsupported, private version of netfilter/iptables which brings all kinds of it's own problems with patches, updates and dependencies.
It really would be much better and supported if you just used shorter names.