SnapGear 1.7.8 Eth0, Eth1, Ppp, Ipsec, Default Deny, Invalid, Smurf, Spoof, SynFlood, Custom

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Commonly used interfaces are:
eth0	the LAN port
eth1	the WAN/Internet port
pppX	eg. ppp0 or ppp1 – a PPP session
ipsecX	eg. ipsec0, an IPSec interface

The firewall rules deny all packets arriving from the WAN port by default. There are a few ports open to deal with traffic such as DHCP, VPN services and similar. Any traffic that does not match the exceptions however is dropped.

There are also some specific rules to detect various attacks (smurf, teardrop, etc.).

When outbound traffic (from LAN to WAN) is blocked by custom rules configured in the GUI, the resultant dropped packets are also logged.

The <prefix> for all these rules is varied according to their type.

Currently used prefixes for traffic arriving:

Default Deny	Packet didn't match any rule – drop it
Invalid	Invalid packet format detected
Smurf	Smurf attack detected
Spoof	Invalid IP address detected
SynFlood	SynFlood attack detected
Custom	Custom rule dropped outbound packet

A typical Default Deny: will thus look similar to the following:

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Appendix B – System Log

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Contents Rev May 2nd Table of contents Virtual Private Networking Introduction Terminology Term MeaningLAN Document conventions TCP/IPInstalling and configuring your SnapGear appliance Step ChapterLEDs Your SnapGear applianceLabel Activity Description SnapGear appliance back panels Network interconnections SnapGear appliance features Software featuresLAN link features Internet link featuresDial-in connection features Environmental features Static IP reset Getting startedNew Networks 10.0.0.0 10.255.255.255 10/8 prefix192.168.0.0 192.168.0.255 192.168.0/24 prefix Configuring the SnapGear appliance on your network Page Set up IP addresses Your SnapGear appliance was found on the network Multiple SnapGear appliances were found on the networkYour SnapGear appliance needs an IP address Administrative password SnapGear Management Console web administration pagesInitial setup using Linux Using linsetipUsing an existing local Dhcp or Bootp server Ping -b subnet broadcast address Arp -aConfiguring a new local Dhcp or Bootp server Edit the /etc/inetd.conf fileSnapGear Quick Setup LAN port quick setup LAN port quick setupISP connection quick setup ISP connection quick setupGetting started Configuring the PCs on your network TCP/IP properties Connecting to the Internet Physically connect modem deviceConnect to Internet cable modem Select Internet connectionConnect to Internet Adsl Connect to Internet direct Connect to Internet modemISP. The Password and Confirm Password fields must Field DescriptionAdvanced configuration option Internet failoverFollowing figure shows the failover configuration screen Failed connection Configure PCs to use SnapGear appliance Internet gateway Establishing the connectionDial-in server configuration Dial-in server configuration Dial-in setup Dial-in setupField Description Dial-in user accounts Dial-in user account creationFollowing figure shows the user maintenance screen Dial-in password error Account listRemote user configuration For Windows 95 and WindowsServer types Windows Connect to dialogue boxClick Next to continue 11 Connection availability 13 Remote access login screen Network configuration IP configurationNetwork configuration Advanced IP configuration Advanced IP configurationNetwork configuration Dhcp server configuration Dhcp serverNetwork configuration Traffic shaping Advanced networkingAdditional routes Incoming access FirewallIncoming access administration services Incoming access configurationExternal access to services Configure external access to servicesPort forwarding configuration Port forwardingOutgoing access Security group classes configurationOutgoing access settings Firewall rulesIntrusion detection and blocking configuration Intrusion detection and blockingPage Content filtering Content filtering Filtering levels and reporting Filtering Level Description1VPN tunneling using the Pptp server Virtual Private NetworkingPptp client setup Pptp client configuration Pptp server setup Enable and configure the Pptp VPN server Pptp server setupField Description Configuring user accounts for VPN server 4PPTP VPN server accounts screenVirtual Private Networking Configuring the remote VPN client VPN Pptp IP addressVirtual Private Networking VPN client setup Windows 95 and WindowsYour VPN client is now set up correctly Windows NT Network and dial-up connections This displays the Destination Address window Connecting the remote VPN client IPSec setup 12 IPSec setup13 Add new IPSec connection Virtual Private Networking 14 Automatic keying setup Aggressive mode phase 1 settings Technique DescriptionIPSec interoperability System PasswordTime server Diagnostics AdvancedFlash upgrade Reset buttonTechnical support Technical supportAppendix a LED status patterns LED Pattern Status ActionAccess Logging Appendix B System LogDefault Deny Eth0Eth1 PppCreating Custom Log Rules Forward Iptables -I Forward -j LOG -i eth+ -o eth+ -p tcp Administrative Access Logging Rate LimitingBoot Log Messages