# Creating a Profile

You can configure an IP interface dynamically by creating a profile. A profile is a set of characteristics that acts as a pattern that can be dynamically assigned to an IP interface. You can manage a large number of IP interfaces efficiently by creating a profile with a specific set of characteristics. In addition, you can create a profile to assign an IP interface to a virtual router.

A profile can contain one or more of the following characteristics:

- access-route—Enables the creation of host access routes on an interface
- address—Configures an IP address on an interface
- auto-configure—Configures the interface for auto-configure mode
- auto-detect—Configures the interface for auto-detect mode
- directed-broadcast—Enables directed broadcast forwarding
- filter-options-all—Enables filtering of packets with IP options on an interface
- igmp—Configures an IGMP interface
- ignore-df-bit—Specifies that the don’t-fragment bit is ignored
- inactivity-timer—Configures inactivity time for IP interfaces
- inspection—Associates an inspection list to the interface for firewalling
- mtu—Configures the maximum transmission unit for a network
- nat—Configures the interface as inside or outside for Network Address Translation (NAT)
- policy—Assigns a policy to the ingress or egress of an interface
- redirects—Enables transmission of ICMP redirect messages
- route-maps—Configures the interface for route-map processing
- source address validation—Verifies that a packet has been sent from a valid source address
- tcp adjust-mss—Adjusts maximum packet sizes on TCP connections when path MTU detection is not sufficient
- unnumbered—Configures IP on this interface without a specific address
- virtual-router—Specifies a virtual router to which interfaces created by this profile will be attached

Use the profile command from Global Configuration mode to create or edit a profile. See JunosE Link Layer Configuration Guide for information about creating profiles and on other characteristics that can be applied to the profile.

host1(config)#profile acton host1(config-profile)#ip virtual-router warf host1(config-profile)#ip unnumbered atm 3/0

ip access-routes

- Use to enable an access route in a profile.
- Example
  host1(config)#profile foo host1(config-profile)#ip access-routes
- Use the no version to remove the access route.
- See ip access-routes

ip address

- Use to assign an IP address to a profile.
- You must first specify the layer 2 encapsulation before you can set the IP address for serial interfaces.
- Example
  host1(config-if)#ip address 192.56.32.2 255.255.255.0
- Use the no version to remove the IP address assigned to the profile.
- See ip address

ip directed-broadcast

- Use to enable a directed broadcast address in a profile.
- Example
  host1(config-if)#ip directed-broadcast
- Use the no version to remove the directed broadcast address from the profile.
- See ip directed-broadcast

ip mtu

- Use to assign the MTU size sent on an IP interface.
- Example
  host1(config-if)#ip mtu 5000
- Use the no version to remove the assignment from the profile.
- See ip mtu

ip redirects

- Use to enable the sending of redirect messages if the software is forced to resend a packet through the same interface on which it was received.
- Example
  host1(config-if)#ip redirects
- Use the no version to remove the assignment from the profile.
- See ip redirects

ip tcp adjust-mss

- Use to modify the maximum segment size (MSS) for TCP SYN packets traveling through the interface. 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.

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

- Example
  host1(config-if)#ip tcp adjust-mss 5000
- Use the no version to remove the MSS assignment from the profile.
- See ip tcp adjust-mss

ip unnumbered

- Use to 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.
- Example
  host1(config-profile)#ip unnumbered fastEthernet 0/0
- Use the no version to remove the assignment from the profile.
- See ip unnumbered

ip virtual-router

- Use to assign a virtual router to a profile.
- You can configure a virtual router using RADIUS instead of adding one to the profile by using the ip virtual-router command.
- Example
  host1(config-profile)#ip virtual-router VR1
- Use the no version to remove the virtual router assignment.
- See ip virtual-router

profile

- Use to create a profile.
- You specify a profile name with up to 80 characters.
- Example
  host1(config)#profile foo
- Use the no version to remove a profile.
- See profile

## Assigning a Profile

To assign a profile to an interface, use the profile command from Interface mode.

profile

- Use to assign a profile to a PPP interface. The profile configuration is used to dynamically create an upper IP interface.
- Example
  host1(config-if)#interface serial 2/1 host1(config-if)#encapsulation ppp host1(config-if)#profile acton
- Use the no version to remove the assignment from the interface.
- See profile