LAM: Local Area Mobility
Advantages: Allows mobility of a single or multiple addresses onto a different subnet. Essentially, this allows you to take an IP address (10.0.0.1) and put it on a different subnet (172.16.0.1/24) and still maintain the 10.0.0.1 address.
Pros: Easy to setup. Mobility of IP addresses.
Cons: Does not work on the 4500 L3 switches running (cat4500e-ENTSERVICES-M), Version 12.2(54)SG. 6500 switches have not been tested. Potential to allow any IP address on the configured mobility subnet. Essentially, if I plug a device with any IP address I want it will be advertised out from the mobility subnet. You can create acl’s to limit this.
Limitations:Do not move the IP address more than once per second. Potential additional load on the routers. The router that advertises the mobile client out will advertise a host route.
Configuration:
Router(config)# router mobile
Router(config)# interface GiabitEthernet(0/0)
Router(config-if)# ip mobile arp access-group 10
Router(config)# access-list 10 permit 10.10.10.0 0.0.0.255
What this does:
- Enables Mobility on the router
- Enables Mobility on the inside interface of the router with an ACL
- Limits the Mobility Address Range to 10.10.10.0/24
Configuration
Redistribute Mobile Routes:
Router(config)#router bgp 1
Router(config-router)#redistribute mobile
Router(config)#router eigrp 1
Router(config-router)#redistribute mobile metric 10 2000 255 1 1500
Verification:
Router#sh ip route mobile
Codes: L – local, C – connected, S – static, R – RIP, M – mobile, B – BGP
D – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter area
N1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2
E1 – OSPF external type 1, E2 – OSPF external type 2
i – IS-IS, su – IS-IS summary, L1 – IS-IS level-1, L2 – IS-IS level-2
ia – IS-IS inter area, * – candidate default, U – per-user static route
o – ODR, P – periodic downloaded static route, + – replicated route
Gateway of last resort is 0.0.0.0 to network 0.0.0.0
10.0.0.0/8 is variably subnetted, 73 subnets, 7 masks
M 10.10.10.213/32[3/1] via 10.10.10.213, 19:46:26, GigabitEthernet0/0
Router#sh ip int bri
Interface IP-Address OK? Method Status Protocol
GigabitEthernet0/0 172.16.0.250 YES NVRAM up up
Router#sh ip mobile int
IP Mobility interface information:
Interface GigabitEthernet0/0:
IRDP (includes agent advertisement) disabled
Prefix Length not advertised
Lifetime is 36000 seconds
Real World
Application-
Ability to easily move Virtual Machines to another site or subnet without the need to Re-IP them.