I have a 2851 router connected to 3 3750v2 switches and a CradlePoint router.
2851 -> 3750v2 -> 3750v2 -> 3750v2 -> CradlePoint
The 2851 is connected to my Internet and the first two 3750v2 switches are at my home while the third 3750v2 and the CradlePoint are at my neighbors. He has his Internet connection connected to the CradlePoint.
I have SLA configured on my 2851 router so that when (and it does) go down, the SLA then routes all Internet access through my neighbors Internet connection. This works perfectly as needed.
My neighbor wants the same, should his Internet go down, he needs Internet requests to go out via my 2851 router. This used to work when we had a 3550 switch at his house. But, the configuration for IOS 15.0 on the 3750v2 is a bit different.
My neighbor can ping my 2851 just fine and even my Internet router. He can also get a result when he pings 8.8.4.4 source 192.168.0.253 (the switch's IP).
When his Internet goes down, BOTH SLA's show down. Here is his config:
!
ip sla 1
icmp-echo 4.2.2.2
frequency 5
ip sla schedule 1 life forever start-time now
ip sla 2
icmp-echo 192.168.0.253 source-ip 192.168.0.254
frequency 5
ip sla schedule 2 life forever start-time now
ip sla responder
ip sla responder udp-echo ipaddress 192.168.0.1 port 5000
ip sla responder udp-echo ipaddress 192.168.0.253 port 5000
logging esm config
!
!
track 10 ip sla 1 reachability
delay down 1 up 1
!
track 20 ip sla 1 reachability
delay down 1 up 1
!
!
ip route 0.0.0.0 0.0.0.0 192.168.0.1 track 10
ip route 0.0.0.0 0.0.0.0 192.168.0.253 10 track 20
ip route 4.2.2.2 255.255.255.255 192.168.0.1
ip route 8.8.8.8 255.255.255.255 192.168.0.253
!
His Internet is connected to port fa3/0/1 and the connection to my Internet is on port fa3/0/48.
We both have Verizon 4G and 4G modems. There is no other option here.
What changes are needed so that when his 4G modem goes off-line for any reason, the switch directs 0.0.0.0 0.0.0.0.0 out to my 2851 router.
2851 IP 192.168.0.253
3750v2 IP 192.168.0.254
CradlePoint IP 192.168.0.1
As you can see from the traceroutes below, from his switch it does go out my 2851 router for 8.8.8.8 and everything else goes out his router. For some reason the switch has issues going out his router but his workstations are working fine.
Sommer's#traceroute 8.8.8.8
Type escape sequence to abort.
Tracing the route to google-public-dns-a.google.com (8.8.8.8)
1 192.168.0.253 17 msec 0 msec 0 msec
2 192.168.10.1 0 msec 8 msec 0 msec
3 85.sub-66-174-39.myvzw.com (66.174.39.85) 33 msec 59 msec 25 msec
4 202.sub-69-83-39.myvzw.com (69.83.39.202) 42 msec 50 msec 25 msec
5 114.sub-69-83-39.myvzw.com (69.83.39.114) 42 msec 34 msec 25 msec
6 194.sub-69-83-39.myvzw.com (69.83.39.194) 42 msec 42 msec 25 msec
7 176.sub-69-83-33.myvzw.com (69.83.33.176) 34 msec 25 msec 33 msec
8 176.sub-69-83-33.myvzw.com (69.83.33.176) 34 msec 34 msec 41 msec
9 169.sub-69-83-33.myvzw.com (69.83.33.169) 34 msec 25 msec 34 msec
10 30.GigabitEthernet5-1.GW3.TPA2.ALTER.NET (152.179.46.153) 25 msec 42 msec 34 msec
11 0.ae9.GW2.MIA19.ALTER.NET (140.222.231.223) 42 msec
0.ae8.GW2.MIA19.ALTER.NET (140.222.231.225) 42 msec
0.ae9.GW2.MIA19.ALTER.NET (140.222.231.223) 59 msec
12 google-gw.customer.alter.net (152.179.236.242) 42 msec 42 msec 42 msec
13 108.170.249.17 42 msec 42 msec 50 msec
14 108.170.228.17 34 msec
108.170.228.27 42 msec
108.170.228.47 42 msec
15 google-public-dns-a.google.com (8.8.8.8) 51 msec 50 msec 34 msec
Sommer's#traceroute 4.2.2.2
Type escape sequence to abort.
Tracing the route to b.resolvers.Level3.net (4.2.2.2)
1 192.168.0.1 0 msec 0 msec 9 msec
2 192.168.20.1 0 msec 8 msec 0 msec
3 * * *
4 * * *
5 * * *
