Re: Drop original port of redirect/forwarding
"Tsaousis, Costa" <[email protected]> Mon, 7 Mar 2016 21:26:29 +0200
| Newsgroups | gmane.comp.security.firewalls.firehol.user |
|---|---|
| Message-ID | <CANL+VpYMJq5pdc-3oRL7etMZ9a7Zcqh0nfVbH4GFbo+sgJTzfg@mail.gmail.com> |
Hi Alexander, the easiest way is to send tcp/22 to the discard port: redirect to 7 inface ppp+ proto tcp dport 22 There are also more "exotic" ways, like marking the incoming packets on tcp/22222 and accepting only the marked packets on `server ssh accept`. But stick to simplicity, send the illegal packets to the discard port. Costa On Mon, Mar 7, 2016 at 8:40 PM, Alexander Schomburg < [email protected]> wrote: > Hello there, > > I recently discovered FireHOL (which is awesome by the way, thanks!) and > just setup my first FireHOL firewall on a router. Most things work great, > although it is a pity that there are no v2+ packages available in Debian > stable repositories. > > I’m experiencing a configuration issue I don’t know how to solve. How can > I drop IPv4 packages for an interface if there are packages being > redirected to the same port that should be allowed? > > Let’s look at this example: I’m running SSHd on localhost:22. I want my > LAN clients (eth0) to be able to access the SSHd via the default port 22, > but all Internet clients (ppp+) should reach the daemon only via port 22222. > > This is my current config that does work, but still allows Internet > clients (ppp+) to access SSHd via both the default port and port 22222. How > can I drop packages to port 22 that were not redirected from port 22222? > Specifying dport on the „server ssh accept“ will be ignored by FireHOL, > probably because it doesn’t know about the destination port anymore after > redirecting. > > ############################## > version 5 > > redirect to 22 inface ppp+ proto tcp dport 22222 > > interface eth0 lan src 192.168.0.0/24 > policy accept > > interface ppp+ internet src not „192.168.0.0/24 ${UNROUTABLE_IPS}" > protection strong > server ssh accept > server ident reject with tcp-reset > client all accept > > router internet2lan inface ppp+ outface eth0 dst 192.168.0.0/24 > protection strong > server ident reject with tcp-reset > client all accept > masquerade reverse > ############################## > > Thanks for your help and best regards, > > Alex > _______________________________________________ > Firehol-support mailing list > [email protected] > http://lists.firehol.org/mailman/listinfo/firehol-support _______________________________________________ Firehol-support mailing list [email protected] http://lists.firehol.org/mailman/listinfo/firehol-support