Troubleshooting Linux Firewalls

Index

[SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z]

name length

     DNS lookupsnames servers

    running on firewalls         DNS lookup failures 2nd

    running on internal and/or DMZ networks         DNS lookup failures 2nd

NAT     and IPSEC     common questions about 2nd

     listing current NAT and rule packet counters 2nd     listing current NAT entries with iptables 2nd NAT (Network Address Translation)

NAT connections

     viewing with netstat-nat 2nd 3rd 4th

NAT firewalls

     cannot get NFS traffic to traverse 2nd 3rd 4th 5th 6th 7th 8thNAT rules

     internal VPN routing 2nd

     IPSEC connections 2nd     PPTP VPN connections 2nd

NAT Traversal ModeNAT/MASQ firewall

     connections between internal systems and external IPSEC servers 2nd 3rdNAT/MASQ firewalls     IPSEC VPN connections 2nd 3rd

     PPTP VPN connections 2nd 3rd

netfilter 2nd

     fragmentation 2nd

     how it works 2nd

    packets

         forwarding for some other host to some other host (FORWARD)

         sent by firewall from a local process to a remote system (OUTPUT)

         sent to service running on firewall from remote host (INPUT)

     parsing rules 2nd 3rd 4th 5th 6th 7th 8th 9th

netfilter engine

    iptables. [See iptables]

     TCP connections

     UDP connectionsnetfilter firewalls     connecting to remote NetMeeting/GnomeMeeting clients 2nd

netfilter website

netfilters     states 2nd

NetMeeting

     blocking outbound traffic 2nd

     connecting to remote NetMeeting clients from behind iptables firewalls (outbound calls only)

     connecting to remote NetMeeting clients from behind netfilter/iptables firewalls (inbound/outbound calls) 2nd

netstat-nat

     viewing NAT connections 2nd 3rd 4thNetwork Address Translation. [See NAT]

network diagnostics 2nd 3rd 4th 5thNetwork File System. [See NFS]

Network Intrusion Detection System. [See NIDS] network performance settings (kernal options) 2nd

network traffic analyzers 2ndNEW     netfilter

NFS     cannot get NFS traffic to traverse a NAT or IP forwarding firewall 2nd 3rd 4th 5th 6th 7th 8th NFS (Network File System)

ngrep

NIDS (Network Intrustion Detection System) 2nd

nmap 2nd

     network diagnostics 2nd     reading output from 2nd 3rd

    testing

         INSIDE-OUT 2nd 3rd 4th 5th