I have a Comcast Business cable modem/router (SMC) with 13 Static IP Addresses. The SMC that Comcast provides a combo modem and router, so it's already running NAT. The SMC is connected to a LinkSys Switch in order to have more ports than what the SMC (4 ports) provides. I have logging into the web interface 10.1.10.1 and disabled the firewall in order to pass some of the IP addresses to my routers (Two Different Routers on Two of the public IP addresses). Everything has been working as expected until I decided to added a High Availability to a proxy which is on one of the public addresses. This is a Linux Box and I am using Heartbeat for HA.
The two proxy boxes work without any issue as an individual box. I am going to use Box One and Box Two notation in order to distinguish them here. Each boxes also have their own Public IP address XXX.XXX.XXX.XX7 and XXX.XXX.XXX.XX8 for accessing the box. The third IP address is the floating IP address XXX.XXX.XXX.XX9 which is obtained by the Master/Active Box while the Salve/Passive Box will be on hot standby. The two boxes are connected to LinkSys Switch which provides enough port (LinkSys 4124 - 24 port unmanaged switch) for the provided range of public IP addresses and Internet connectivity.
Initial condition is follow:
Box One – Master / Active
Box Two – Slave / Passive (Hot Standby)
On the box one, once the Heartbeat is stopped, the Floating IP address is released, Database is stopped, and finally the remaining services are shutdown in proper order. This event results the box two takes over the Floating IP address by assigning it to the eth0 under aliases eth0:0, starts MySQL database, and finally turn on the other services in proper order. At this point everything appears to be in
perfect working order.
The problem is that the the traffic from the internet cloud continues to be sent to the box one while the traffic from my other boxes connected to the switch have no problem getting to the box two via floating IP address! (eg. I can ssh to the floating IP address from any of the 13 public IP addresses provided by the comcast and get connected to box two while the ssh from an external IP address is sent to the box one. If I wait for 300seconds then everything works fine and traffic from outside get routed to the box two.
My disgnostic shows the issue is the ARP Cache of the Comcast Modem/Router and so far I haven't been able to use gratuitous ARP to update the ARP cache on the SMC.
I would like to know if you guys have come across this issue and would like to know what you think about it.
Thank you in advance for your help.