Configuring Profile Attributes for IP

You can add a specific set of IP characteristics to a created profile and assign the profile to many IP interfaces.

To assign IP characteristics to a profile:

1. Assign an IP address.
   host1(config-profile)#ip address 192.56.32.2 255.255.255.0
2. (Optional) Enable an access route.
   host1(config-profile)#ip access-routes
3. (Optional) Enable a directed broadcast address.
   host1(config-profile)#ip directed-broadcast
4. (Optional) Assign the MTU size sent on an IP interface to which the profile is assigned.
   host1(config-profile)#ip mtu 5000
5. (Optional) Enable the sending of redirect messages if the software is forced to resend a packet through the same interface (to which the profile is assigned) on which it was received.
   host1(config-profile)#ip redirects
6. (Optional) Modify the maximum segment size (MSS) for TCP SYN packets traveling through the interface to which the profile is assigned. The router compares the MSS value of incoming or outgoing packets against the MSS adjustment value. For any packet that contains an MSS value larger than the MSS adjustment value, the router replaces the MSS option with the configured adjustment value. If the packet does not contain an MSS value, the router assumes a value of 536 for the packet MSS on which to base the comparison.
   host1(config-profile)#ip tcp adjust-mss 5000

   Note: The purpose behind using MSS is to alleviate problems with path maximum transmission unit discovery and resulting black hole detection issues. (See RFC 2923, “TCP Problems with Path MTU Discovery,” for additional information about the black hole scenario.)

7. (Optional) Specify the numbered interface with which dynamic unnumbered interfaces created with the profile are associated. You can specify an unnumbered interface using RADIUS instead of using the ip unnumbered command in a profile.
   host1(config-profile)#ip unnumbered fastEthernet 0/0
8. (Optional) Assign a virtual router. You can configure a virtual router using RADIUS instead of adding one to the profile by using the ip virtual-router command.
   host1(config-profile)#ip virtual-router VR1
9. (Optional) Force the router to ignore the DF bit if it is set in the IP packet header for packets on an interface to which the profile is assigned.
   host1(config-profile)#ip ignore-df-bit
10. (Optional) Enable source address validation.
    host1(config-profile)#ip sa-validate