Rate Limiting, Appendix C System Log | SnapGear 2.0.1 instruction

If we just wanted to look at traffic that went out to the IPSec world, we could use:

iptables -I FORWARD -j LOG -o ipsec+

Clearly there are many more combinations possible.

It is therefore possible to write rules that log inbound and outbound traffic, or to construct several rules that differentiate between the two.

Rate Limiting

iptables has the facility for rate-limiting the log messages that are generated, in order to avoid denial of service issues arising out of logging these access attempts. To achieve this, use the following option:

--limit rate

rate is the maximum average matching rate, specified as a number with an optional /second, /minute, /hour, or /day suffix. The default is 3/hour.

--limit-burst number

number is the maximum initial number of packets to match. This number gets recharged by one every time the limit specified above is not reached, up to this number. The default is 5.

iptables has many more options. Perform a web search for manpage iptables to find the relevant documentation.

The LOG rules configured by default (e.g. Default Deny:) are all limited to:

--limit 3/hour --limit-burst 5

182

Appendix C – System Log

Image 186

SnapGear 2.0.1 user manual Rate Limiting, Appendix C System Log

Contents

Revision June 7 Contents Firewall 104 170 159169 177 Introduction CyberGuard SG Gateway AppliancesIntroduction CyberGuard SG PCI Appliances Bridged mode Secure by default Text like this highlights important issues Document Conventions Your CyberGuard SG Gateway Appliance Front panel LEDsSG300 model includes two blue straight through UTP cables Virtual Private Networking is enabled Rear panel LAN link features CyberGuard SG Gateway Appliance FeaturesInternet link features DMZ link features SG570, SG575 only Your CyberGuard SG PCI Appliance LEDs CyberGuard SG PCI Appliance Features Network link featuresEnvironmental features Getting Started 192.168.0.1 255.255.255.0Page Right click on Local Area Connection and select Properties Set up the Password and LAN Connection Settings 192.168.0.100 Root Getting Started Getting Started Analog modem Set up Internet Connection SettingsCable modem DSL modem Set up the PCs on your LAN to Access the Internet LAN with a Dhcp server LAN with no Dhcp server To manually set up each Windows PC on your network Select Dhcp Server from the Networking menu Getting Started Install the Network Driver on your PC Set up your PC to Connect to the Web Management Console Select Internet Protocol TCP/IP and click Properties Select Use the following DNS server addresses and enter Set up the Password and Network Connection Settings Network Setup Connections page will display Click Apply and Reboot Ensure Dhcp assigned is unchecked Getting Started Click Apply and Reboot Getting Started Page Network Connections ConnectionsNetwork Connections LAN Bridging Internet Internet Connection Methods Physically connect modem deviceCable Direct Internet Bridged Internet COM/Modem Failover Direct/Cable/ADSL InternetDialout Internet ISP. The Password and Confirm Password fields must Field DescriptionOptional Dialin access Direct DMZBridged DMZ Bridged LAN Services on the DMZ NetworkDirect LAN DMZ as a second Internet connection DMZ as a backup/failover Internet connection Load BalancingInternet Failover Enable the primary connection for failover Set up a secondary backup Internet connection Network Connections Routes Additional routesRoute management Advanced HostnameDNS Proxy Network Address Translation NAT/masquerading Dynamic DNS Interface aliases QoS Traffic Shaping Change MAC address Dialin Setup Dialin Setup Dialin Setup Following table describes the fields on the Dial-In Setup Dialin User Accounts Account list Page Remote User Configuration Windows 95/98/Me Dialin Setup Windows 2000/XP Dialin Setup Page Dhcp Server Configuration Dhcp ServerDhcp Server Dhcp Server Interface Enable/DisableSubnet List Subnet Dhcp Server Dhcp Proxy Incoming Access FirewallFirewall Administration services CyberGuard SG Administrative Web Server SSL/HTTPS Secure Http SSL Certificate Setup Add Local and Private Certificates Outgoing Interface Packet FilteringIncoming Interface Action Addresses Service groups Rules Enable Destination NAT/port forwardingDescriptive Name Source Address Destination ServicesSource NAT Destination Address To-1 NAT Rules Access Control and Content Filtering User authenticationPage Browser setup Click Advanced IP lists Web lists Content Reports Categories ZoneAlarm Intrusion Detection Intrusion Detection Benefits of using an IDS Basic Intrusion Detection and Blocking Page Advanced Intrusion Detection Advanced Intrusion Detection configuration Intrusion Detection Setting up the analysis server Page Web Cache Web cache is only available on SG575 modelsWeb Cache Web Cache Setup Cache size Network Shares Create a new user account100 Web Cache Create the network share 101 Web Cache Set the CyberGuard SG appliance to use the network share 102 Web Cache Set up LAN PCs to Use the Web Cache Peers103 Web Cache Virtual Private Networking 104 Virtual Private Networking Pptp Client Setup 106 Virtual Private Networking Pptp Server Setup 107 Virtual Private Networking Enable and configure the Pptp VPN server 108 Virtual Private Networking Data private as well as providing secure authentication Encryption is strongly recommended. This keeps your109 Virtual Private Networking Configuring user accounts for VPN server 111 Virtual Private Networking Configuring the remote VPN client 112 Virtual Private Networking Windows 95, Windows 98 and Windows Me Windows 114 Virtual Private Networking 115 Virtual Private Networking Windows XP 116 Virtual Private Networking Connecting the remote VPN client 117 Virtual Private Networking CyberGuard SG appliance to CyberGuard SG appliance IPSec SetupSet up the Branch Office Enabling IPSec 119 Virtual Private Networking Configure a tunnel to connect to the headquarters office Tunnel settings120 Virtual Private Networking 121 Virtual Private Networking 122 Virtual Private Networking Local endpoint settings 123 Virtual Private Networking 124 Virtual Private Networking Other options 125 Virtual Private Networking 126 Virtual Private Networking 127 Virtual Private Networking Tcgid 128 Virtual Private Networking Phase 1 settings Kept confidential129 Virtual Private Networking 130 Virtual Private Networking Phase 2 settings 131 Virtual Private Networking Configuring the Headquarters 132 Virtual Private Networking 133 Virtual Private Networking Remote endpoint settings Leave the Enable IP Payload Compression checkbox unchecked134 Virtual Private Networking 135 Virtual Private Networking Remote party Tunnel ListConnection 136 Virtual Private Networking Status 137 Virtual Private Networking 138 Virtual Private Networking 139 Virtual Private Networking NAT Traversal Support Dynamic DNS Support140 Virtual Private Networking Certificate Management Extracting certificates141 Virtual Private Networking Creating certificates 142 Virtual Private Networking Create the self-signed root CA certificate 143 Virtual Private Networking Adding certificates 144 Virtual Private Networking Adding a CA or CRL certificate 145 Virtual Private Networking Adding a local certificate 146 Virtual Private Networking Troubleshooting 147 Virtual Private Networking 148 Virtual Private Networking 149 Virtual Private Networking 150 Virtual Private Networking LAN address Setting up a GRE tunnelCyberGuard SG appliance in Brisbane Internet address CyberGuard SG appliance in Slough Internet address Remote subnet/netmask 10.1.0.0 GRE over IPSec 154 Virtual Private Networking Local Internal Address Place on Ethernet Bridge 155 Virtual Private Networking Troubleshooting 156 Virtual Private Networking L2TP VPN client 157 Virtual Private Networking L2TP server 158 Virtual Private Networking Set date and time SystemDate and Time NTP time server Locality 160 System Users 161 System Encrypted save/restore all AdministrationDiagnostic User settings Password DiagnosticsInternet access via access controls Diagnostics Network tests 164 System Configuration files System log165 System Flash upgrade Reboot Reset button Technical Support Appendix a IP Address Ranges B.c.d B.c.d-e B.c.d-e.f.g.h B.c.d/e169 Appendix a IP Address Ranges Appendix B Terminology Term Meaning170 Appendix B Terminology DNS 171 Appendix B Terminology IDB 172 Appendix B Terminology Isakmp 173 Appendix B Terminology NTP 174 Appendix B Terminology SHA 175 Appendix B Terminology 176 Access Logging Appendix C System Log Eth1 Default DenyEth0 Ppp Creating Custom Log Rules 179 Appendix C System Log 180 Appendix C System Log Iptables -I Forward -j LOG -i eth0 -p tcp 181 Appendix C System Log Rate Limiting 182 Appendix C System Log Administrative Access Logging Boot Log Messages183 Appendix C System Log Appendix D Firmware Upgrade Practices and Precautions 184 Appendix D Firmware Upgrade Practices and Precaut ions