SGS-6341-Series User Manual

be a virtual link between backbone Layer 3 Switch10 and Switch
11. The area edge Layer 3
switches exchange summary information via the backbone Layer 3 switch, each area edge
Layer 3 switch listens to the summary information from the other edge Layer 3 switches.
Virtual link can not only maintain the connectivity of the backbone area, but also strengthen the
backbone area. For example, if the connection between backbone Layer 3 SwitchG and
Switch10 is cut down, the backbone area will become incontinuous. The backbone area can
become more robust by establishing a virtual link between backbone Layer 3 switches SwitchF
and Switch10. In addition, the virtual link between SwitchF and Switch10 provide a short path
from area 3 to Layer 3 Switch F.
Take area 1 as an example. Assume the IP address of Layer 3 SwitchA is 10.1.1.1, IP address
of Layer 3 Switch B interface VLAN2 is 10.1.1.2, IP address of Layer 3 SwitchC interface
VLAN2 is 10.1.1.3, IP address of Layer 3 SwitchD interface VLAN2 is 10.1.1.4. SwitchA is
connecting to network N1 through Ethernet interface VLAN1 (IP address 20.1.1.1); SwitchB is
connecting to network N2 through Ethernet interface VLAN1 (IP address 20.1.2.1); SwitchC is
connecting to network N4 through Ethernet interface VLAN3 (IP address 20.1.3.1). All the
three addresses belong to area 1. SwitchC is connecting to Layer 3 SwitchE through Ethernet
interface VLAN1 (IP address 10.1.5.1); SwitchD is connecting to Layer 3 SwitchD through
Ethernet interface VLAN1 (IP address 10.1.6.1); both two addresses belong to area 1. Simple
authentication is implemented among Layer 3 switches in area1, edge Layer 3 switches of
area 1 authenticate with the area 0 backbone Layer 3 switches by MD5 authentication.
The followings are just configurations for all Layer 3 switches in area 1, configurations for
Layer 3 switches of the other areas are omitted. The following are the configurations of
SwitchA, SwitchB, SwitchC and SwitchD:
1)Switch A:
Configure IP address for interface vlan2
SwitchA#config
SwitchA(config)# interface vlan 2
SwitchA(config-If-Vlan2)# ip address 10.1.1.1 255.255.255.0
SwitchA(config-If-Vlan2)#exit
Enable OSPF protocol, configure the area number for interface vlan2.
SwitchA(config)#router ospf
SwitchA(config-router)#network 10.1.1.0/24 area 1
SwitchA(config-router)#exit
Configure simple key authentication.
SwitchA(config)#interface vlan 2
SwitchA(config-If-Vlan2)#ip ospf authentication
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User’s Manual of SGS-6341 series