Configuring multicast load sharing on Checkpoint Firewalls running ClusterXL when the routers/switches on either side of the firewalls are Cisco devices has always been a mystery. Checkpoint has support articles on how to configure them but there is no straight forward direction on their website or documentation. The documentation points to older Cisco models. This techtorial will try to give a brief overview of the commands and procedure involved in getting multicast load sharing working.
Consider the simple network shown below:You have three firewall enforcement points in a cluster whose internal and external VIPs (Virtual IP addresses) are as given. Traffic flows from internal network via the internal router and switch to firewall cluster and on to the external network. All three firewalls are supposed to receive the traffic and any one of them will process the traffic depending on the ClusterXL load sharing algorithm. And same happens for traffic in the opposite direction. At least theoretically thats what is supposed to happen. But when its comes to Cisco devices which are involved in the traffic processing, Cisco routers do not like to forward a frame to a mulitcast MAC address if they get that MAC address back while sending an arp request for the next hop. In the diagram shown above, the next hop for the Cisco router is the internal VIP of the firewall cluster (going out to the internet). If the MAC address returned to the router in its arp query is a mulitcast address it will not take it and put it in the arp table and forward the frame. Same is true on the external side of the firewall too where the external VIP of the firewall cluster is the next hop for the Cisco router when traffic is coming back into the network.
The only way to resolve this issue is to configure static MAC address entries on the Cisco routers and switches and also disable IGMP snooping on the vlans to which the the firewall cluster interfaces and the router interfaces are connected. So for the above show diagram you would have to do the following:
- Configure the following command on the internal router:
- arp 192.168.20.2 0100.5e16.0de2 arpa
- Configure the following commands on the internal switch where the port numbers shown below are the port numbers to which your firewall interfaces are connected:
- mac address-table static 0100.5e16.0de2 vlan 10 interface gi1/0/2 gi1/0/3 gi1/0/4
- no ip igmp snooping vlan 10
- The multicast mac address of the firewall cluster's internal VIP (shown above in the commands) is obtained by looking at the topology information of the cluster in the SmartDashboard and clicking on the edit option for the cluster IP and then clicking on the advanced button. That should show you the mulitcast MAC address. Checkpoint has an sk technote which shows a different way of getting the MAC address using the cphaconf debug_data command on the command line. This DOES NOT work as it gives you the wrong MAC address.
- The same configuration commands (with the correct IP and MAC for the external cluster) are performed on the external router pointing to the external VIP:
- arp 192.168.15.2 0100.5e16.0de3 arpa
- And the same configuration command on the external switch:
- mac address-table static 0100.5e16.0de3 vlan 20 interface gi1/0/5 gi1/0/6 gi1/0/7
- no ip igmp snooping vlan 20
Thanks for this scripts on multi-cast firewall setting. I can say that this hierarchy model suites the firewall structure.
ReplyDeletereally clean documentation which i have not seen anywhere as clear as this
ReplyDeleteYou can also obtain the multicast MAC address of each interface with "cphaprob igmp"
ReplyDelete
ReplyDeletegood blog.
Cloud Based Firewall
CISCO Firewall
nice
ReplyDeleteCISCO Routers
Play Coin Casino at Changyong Online Casino
ReplyDeletePlay at Coin Casino online in 바카라 사이트 Changyong with 코인카지노 a range of casino games including Slots, Blackjack, Roulette and Live Casino クイーンカジノ Games.
Casino City by Wyndham - MapyRO
ReplyDeleteCasino City by Wyndham: Information, 부천 출장마사지 timings, location, contact, 의왕 출장안마 map 충주 출장안마 and more for Casino 통영 출장마사지 City, including 광명 출장마사지 driving directions, driving directions,
Harrahs Casino - Jordan 16 Retro
ReplyDeleteHarrahs Casino has a huge range of slot machines in the rooms. They have a selection of over 700 air jordan 18 retro online store titles that have how to buy air jordan 18 retro toro mens sneakers different types of game. air jordan 1 retro high og university blue You jordan 18 white royal blue good website can play air jordan 18 retro red to my site at Harrah's