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Cisco Router Guru - Complex Multi-ISP Configuration
I have a customer who wants redundancy with multiple ISP connections. I am very familiar with how to configure a single ISP connection (with Cisco router) with one or more Global IP addresses, with NAT and overloaded NAT (PAT), I know how to configure GRE tunnels, and access-lists, but what I need is how to configure the following:
" Cisco 2811 12.4(3c), 4 x FastEthernet, 256mb
" ISP #1, Static IPs 201.1.1.40/29, gw: 201.1.1.41, 5 usable .42 -> .46 (DS3, 45mbps/45mbps BGP with #2)
" ISP #2, Static IPs 202.2.2.64/29, gw: 202.2.2.65, 5 usable .66 -> .70 (Fiber, 20mbps/5mbps BGP with #1)
" ISP #3, Static IPs 203.3.3.80/29, gw: 203.3.3.81, 5 usable .82 -> .86 (Cable, 8mbps/1mbps No BGP avail)
" ISP #4, Static IPs 204.4.4.92/30, gw: 204.4.4.93, 1 usable .94 (DSL, 4mbps/384kbps No BGP avail)
" ISP #5, Dynamic IP, single IP (Aircard, 1mbps)
DNS:
" www.myweb.com -> 201.1.1.43 (ports 80, 443)
" mail.myweb.com -> 201.1.1.44 (ports 25, 110)
" ts.myweb.com -> 201.1.1.45 (ports 3389, GRE)
Router Interface:
" FastEthernet 1 -> 201.1.1.42
" FastEthernet 2 -> 202.2.2.66
" FastEthernet 3 -> 203.3.3.82
" FastEthernet 4 -> 204.4.4.94
Object:
" ISP #1 and #2 to use BGP to resolve each others routing path to client (I know this is something that has to be arranged with ISP #1 and #2)
" ISP #3 has 5 global IP, but no BGP
" ISP #4 has only 1 global IP, and no BGP
" Is it possible to configure a higher routing metric value during BGP configuration to send 201.1.1.40/29 traffic to 203.3.3.145 and 202.2.2.64/29 traffic to 203.3.3.145 ??
" ISP #5 will never be used for inbound traffic
" Outbound traffic needs to return by whatever path it came in on (is this necessary??)
" If ISP #1, 2, 3, and 4 are all down, then outbound traffic will use ISP #5 (on demand aircard on different router)
" GRE Tunnels exist between 2 remote sites, with Cisco routers, 222.1.1.21 (Lan 192.168.21.0/24) and 233.1.1.23 (Lan 192.168.22.0/24)
" Local Lan is 172.16.0.0/16
" Tunnel traffic between local lan (172.16.0.0/16) and tunnels (192.168.21.0/24 and 192.168.22.0/24) should live as long as at least one WAN interface is up
" Aircard (for outbound traffic if ISP #1, #2, #3, #4 down) is on Lan 172.16.1.5 & so all outbound traffic should be sent to this IP only if all 4 of the WAN interfaces are down (the aircard is connected to its own router with NAT)
End result:
" If at least one WAN interface is up, all inbound/outbound traffic and GRE tunnel traffic will flow normally, without interruption even if the main ISP goes down, traffic will continue, automatically & must check for keep-alive (or something), because cannot depend on interface getting a down status from ISP & it may just stop passing traffic
I know this is a rather complex configuration, but a 2 ISP scenario is probably common. If there are any routing gurus who have done this, or similar, it would really help me, and possibly others, if you know a solution to this. Many (many) thanks in advance.
" Cisco 2811 12.4(3c), 4 x FastEthernet, 256mb
" ISP #1, Static IPs 201.1.1.40/29, gw: 201.1.1.41, 5 usable .42 -> .46 (DS3, 45mbps/45mbps BGP with #2)
" ISP #2, Static IPs 202.2.2.64/29, gw: 202.2.2.65, 5 usable .66 -> .70 (Fiber, 20mbps/5mbps BGP with #1)
" ISP #3, Static IPs 203.3.3.80/29, gw: 203.3.3.81, 5 usable .82 -> .86 (Cable, 8mbps/1mbps No BGP avail)
" ISP #4, Static IPs 204.4.4.92/30, gw: 204.4.4.93, 1 usable .94 (DSL, 4mbps/384kbps No BGP avail)
" ISP #5, Dynamic IP, single IP (Aircard, 1mbps)
DNS:
" www.myweb.com -> 201.1.1.43 (ports 80, 443)
" mail.myweb.com -> 201.1.1.44 (ports 25, 110)
" ts.myweb.com -> 201.1.1.45 (ports 3389, GRE)
Router Interface:
" FastEthernet 1 -> 201.1.1.42
" FastEthernet 2 -> 202.2.2.66
" FastEthernet 3 -> 203.3.3.82
" FastEthernet 4 -> 204.4.4.94
Object:
" ISP #1 and #2 to use BGP to resolve each others routing path to client (I know this is something that has to be arranged with ISP #1 and #2)
" ISP #3 has 5 global IP, but no BGP
" ISP #4 has only 1 global IP, and no BGP
" Is it possible to configure a higher routing metric value during BGP configuration to send 201.1.1.40/29 traffic to 203.3.3.145 and 202.2.2.64/29 traffic to 203.3.3.145 ??
" ISP #5 will never be used for inbound traffic
" Outbound traffic needs to return by whatever path it came in on (is this necessary??)
" If ISP #1, 2, 3, and 4 are all down, then outbound traffic will use ISP #5 (on demand aircard on different router)
" GRE Tunnels exist between 2 remote sites, with Cisco routers, 222.1.1.21 (Lan 192.168.21.0/24) and 233.1.1.23 (Lan 192.168.22.0/24)
" Local Lan is 172.16.0.0/16
" Tunnel traffic between local lan (172.16.0.0/16) and tunnels (192.168.21.0/24 and 192.168.22.0/24) should live as long as at least one WAN interface is up
" Aircard (for outbound traffic if ISP #1, #2, #3, #4 down) is on Lan 172.16.1.5 & so all outbound traffic should be sent to this IP only if all 4 of the WAN interfaces are down (the aircard is connected to its own router with NAT)
End result:
" If at least one WAN interface is up, all inbound/outbound traffic and GRE tunnel traffic will flow normally, without interruption even if the main ISP goes down, traffic will continue, automatically & must check for keep-alive (or something), because cannot depend on interface getting a down status from ISP & it may just stop passing traffic
I know this is a rather complex configuration, but a 2 ISP scenario is probably common. If there are any routing gurus who have done this, or similar, it would really help me, and possibly others, if you know a solution to this. Many (many) thanks in advance.
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