IP route exchange protocols

The switch supports the following IP route exchange protocols:

  • Routing Information Protocol (RIP)

  • Open Shortest Path First (OSPF)

  • ICMP Router Discovery Protocol (IRDP)

  • Dynamic Host Configuration Protocol (DHCP) Relay

These protocols provide routes to the IP route table. You can use one or more of these protocols, in any combination. The protocols are disabled by default. For configuration information, see the following:

IP global parameters for routing switches

IP global parameters for routing switches lists the IP global parameters and the page where you can find more information about each parameter.

IP global parameters for routing switches

Parameter Description Default See page
Router ID The value that routers use to identify themselves to other routers when exchanging route information.

OSPF uses the router ID to identify routers.

RIP does not use the router ID.

The lowest-numbered IP address configured on the lowest-numbered routing interface. Changing the router ID
Address Resolution Protocol (ARP) A standard IP mechanism that routers use to learn the MAC address of a device on the network. The router sends the IP address of a device in the ARP request and receives the device's MAC address in an ARP reply. Enabled Configuring ARP parameters
ARP age The amount of time the device keeps a MAC address learned through ARP in the device's ARP cache. The device resets the timer to zero each time the ARP entry is refreshed and removes the entry if the timer reaches the ARP age. (Can be set using the menu interface to be as long as 1440 minutes. Go to Menu Switch Configuration IP Config.)

See Increasing ARP age timeout (CLI).

Five minutes. N/A
Proxy ARP An IP mechanism a router can use to answer an ARP request on behalf of a host, by replying with the router's own MAC address instead of the host's. Disabled About enabling proxy ARP
Time to Live (TTL) The maximum number of routers (hops) through which a packet can pass before being discarded. Each router decreases a packet's TTL by 1 before forwarding the packet. If decreasing the TTL causes the TTL to be 0, the router drops the packet instead of forwarding it. 64 hops See the Management and Configuration Guide for your switch.
Directed broadcast forwarding A directed broadcast is a packet containing all ones (or in some cases, all zeros) in the host portion of the destination IP address. When a router forwards such a broadcast, it sends a copy of the packet out each of its enabled IP interfaces.

[NOTE: ]

NOTE: You also can enable or disable this parameter on an individual interface basis. See IP interface parameters — routing switches.


Disabled Enabling forwarding of directed broadcasts
ICMP Router Discovery Protocol (IRDP) An IP protocol that a router can use to advertise the IP addresses of its router interfaces to directly attached hosts. You can enable or disable the protocol at the Global CLI Config level.

You also can enable or disable IRDP and configure the following protocol parameters on an individual VLAN interface basis at the VLAN Interface CLI Config level.

  • Forwarding method (broadcast or multicast)

  • Hold time

  • Maximum advertisement interval

  • Minimum advertisement interval

  • Router preference level

Disabled A-21

A-159

Static route An IP route you place in the IP route table. No entries A-25
Default network route The router uses the default network route if the IP route table does not contain a route to the destination. Enter an explicit default route (0.0.0.0 0.0.0.0 or 0.0.0.0/0) as a static route in the IP route table. None configured A-30

IP interface parameters for routing switches

IP interface parameters — routing switches lists the interface-level IP parameters for routing switches.

IP interface parameters — routing switches

Parameter Description Default See page
IP address A Layer 3 network interface address; separate IP addresses on individual VLAN interfaces. None configured [*]
Metric A numeric cost the router adds to RIP routes learned on the interface. This parameter applies only to RIP routes. 1 (one) A-33
ICMP Router Discovery Protocol (IRDP) Locally overrides the global IRDP settings. Disabled A-159
IP helper address The IP address of a UDP application server (such as a BootP or DHCP server) or a directed broadcast address. IP helper addresses allow the routing switch to forward requests for certain UDP applications from a client on one subnet to a server on another subnet. None configured A-164

[*] See the Management and Configuration Guide for your switch.