Accton Technology ES4710BD manual Stub cost, Virtuallink neighborid, Show ip ospf

ES4710BD 10 Slots L2/L3/L4 Chassis Switch

18.4.2.2.20 stub cost

Command: stub cost <cost> area <area_id > no stub area <area_id >

Function: Sets an area to STUB area; the “no stub area <area_id >” command cancels the setting.

Parameters: <cost> is the default route cost for the STUB area, ranging from 1 to 65535; <area_id> is the area number of the STUM area, ranging from 1 to 4,294,967,295.

Default: No STUB area is configured by default.

Command Mode: OSPF protocol configuration mode

Usage Guide: An area can be configured to a STUB area if the area has only one egress point (connect to one layer 3 switch only), or need not select egress point for each exterior destination. Type4 LSA (ASBR summary LSA) and type5 LSA (AS exterior LSA) are not allowed to flood into/through STUB areas, this saves the resource for processing exterior routing information for layer 3 switches inside the area.

Example: Setting area 1 to be a STUB area with a default routing cost of 60. Switch(Config-Router-Ospf)#stub cost 60 area 1

18.4.2.2.21 virtuallink neighborid

Command: virtuallink neighborid <router_id> transitarea <area_id> [hellointerval <time>] [deadinterval <time>] [retransmit<time>] [transitdelay <time>]

no virtuallink neighborid <router_id> transitarea <area_id>

Function: Creates and configures a virtual link; the “no virtuallink neighborid <router_id> transitarea <area_id>” command deletes a virtual link.

Parameters: <router_id> is the ID for the virtual link neighbor in decimal format; <area_id> is the area number for transit area, ranging from 0 to 42,949,67,295; the last four parameters are optional intervals that have the same meaning as those in OSPF interface mode.

Default: No virtual link is configured by default.

Command Mode: OSPF protocol configuration mode

Usage Guide: The introduction of virtual link is to fulfill or enhance the connectivity of the backbone area (area 0). As the backbone area must be kept connected logically, if no in-area route exists between two nodes within the backbone area, a virtual link must be established between the two nodes across a transit area. Virtual links are identified by the ID of the partner layer 3 swtich. The non-backbone area providing interior route for both ends of the virtual link is referred to a “transit area”, the area number must be specified on configuration.

A virtual link is activated when the route across the transit area is calculated, and practically forms a point-to-point connection between the two ends. In this connection, interface parameters (such as HELLO interval) can be configured just as on a physical interface.

Example: Configuring a virtual link to 11.1.1.1 via transit area 2. Switch(Config-Router-Ospf)#virtuallink neighborid 11.1.1.1 transitarea 2

18.4.2.2.22 show ip ospf

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