Running RH7.0 on an IntelliStation attached to corp. LAN. via tr0 (9.xx.xx.xx). I have users who telnet into this Linux box via the LAN and use minicom/dip to dial out sl0 (ttyS0).
I want to setup a firewall on this server so that:
All inbound requests on sl0 are denied.
All outbound requests on sl0 except telnet and ftp (port 20/21) are denied.
All inbound requests on tr0 except telnet denied.
All outbound requests on tr0 except telnet and ftp are denied.
Would like your thoughts and examples on this.