Allied Telesis AT-WR4500 manual Virtual Links, Submenu level /routing ospf interface

102	AT-WR4500 Series - IEEE 802.11abgh Outdoor Wireless Routers
	RouterOS v3 Configuration and User Guide

5.3.5 Interfaces

Submenu level: /routing ospf interface

Description

This facility provides tools for additional in-depth configuration of OSPF interface specific parameters. You do not have to configure interfaces in order to run OSPF

Property Description

authentication-key(text; default: "") - authentication key have to be used by neighboring routers that are using OSPF's simple password authentication

cost (integer: 1..65535; default: 1) - interface cost expressed as link state metric

dead-interval(time; default: 40s) - specifies the interval after which a neighbor is declared as dead. The interval is advertised in the router's hello packets. This value must be the same for all routers and access servers on a specific network

hello-interval(time; default: 10s) - the interval between hello packets that the router sends on the interface. The smaller the hello-interval, the faster topological changes will be detected, but more routing traffic will ensue. This value must be the same on each end of the adjacency otherwise the adjacency will not form

interface (name; default: all) - interface on which OSPF will run all - is used for the interfaces not having any specific settings

priority (integer: 0..255; default: 1) - router's priority. It helps to determine the designated router for the network. When two routers attached to a network both attempt to become the designated router, the one with the higher router's priority takes precedence

retransmit-interval(time; default: 5s) - time between retransmitting lost link state advertisements. When a router sends a link state advertisement (LSA) to its neighbor, it keeps the LSA until it receives back the acknowledgment. If it receives no acknowledgment in time, it will retransmit the LSA. The following settings are recommended: for Broadcast network are 5 seconds and for Point-to-Point network are 10 seconds

transmit-delay(time; default: 1s) - link state transmit delay is the estimated time it takes to transmit a link state update packet on the interface

Example

To add an entry that specifies that ether2 interface should send Hello packets every 5 seconds, do the following:

[admin@AT-WR4562] routing ospf> interface add interface=ether2 hello-interval=5s

[admin@AT-WR4562] routing ospf> interface print

0 interface=ether2 cost=1 priority=1 authentication-key="" retransmit-interval=5s transmit-delay=1s hello-interval=5s dead-interval=40s

[admin@AT-WR4562] routing ospf>

5.3.6 Virtual Links

Submenu level: /routing ospf virtual-link

Description

As stated in OSPF RFC, the backbone area must be contiguous. However, it is possible to define areas in such a way that the backbone is no longer contiguous. In this case the system administrator must restore backbone connectivity by configuring virtual links. Virtual link can be configured between two routers through common area called transit area, one of them should have to be connected with backbone. Virtual links belong to the backbone. The protocol treats two routers joined by a virtual link as if they were connected by an unnumbered point-to-point network