VRF-Lite Questions
March 23rd, 2020
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Question 1
Explanation
An example of the “show ip vrf” is shown below:
Question 2
Question 3
Question 4
Explanation
In VRF-Lite, Route distinguisher (RD) identifies the customer routing table and “allows customers to be assigned overlapping addresses”. The below example shows overlapping IP addresses configured on two interfaces which belong to two different VPNs:
| Router(config)#ip vrf VRF_BLUE Router(config-vrf)# rd 100:1 Router(config-vrf)# exit Router(config)#ip vrf VRF_GREEN Router(config-vrf)# rd 100:2 Router(config-vrf)# exit Router(config)# interface GigabitEthernet0/1 Router(config-if)# ip vrf forwarding VRF_BLUE Router(config-if)# ip address 10.0.0.1 255.0.0.0 Router(config-vrf)# exit Router(config)# interface GigabitEthernet0/2 Router(config-if)# ip vrf forwarding VRF_GREEN Router(config-if)# ip address 10.0.0.1 255.0.0.0 |
In this example, the RD will be added to the beginning of the IP address. For example with VRF_BLUE (rd 100:1), an IP address will be seen like this: 100:1:10.0.0.1/8 so that it is unique in the routing table.
Question 5
Question 6
Explanation
The first command “R1(config)# ip vrf Inet” creates vrf Inet while the two last commands associate the VRF with interface Fa0/0.
Question 1
A is correct.
COMMAND: Switch# show ip vrf [brief | detail | interfaces] [vrf-name]
PURPOSE: Displays information about the defined VRF instances.
COMMAND: Switch# show ip protocols vrf vrf-name
PURPOSE: Displays routing protocol information associated with a VRF.
COMMAND: Switch# show ip route vrf vrf-name [connected]
PURPOSE: Displays IP routing table information associated with a VRF.
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/12-2/15-02SG/configuration/guide/config/vrf.html
Q2
Just FYI: Most routing protocols (BGP, OSPF, EIGRP, RIP and static routing) can be used between the CE and the PE. However, we recommend using external BGP (EBGP) for these reasons:
–BGP does not require multiple algorithms to communicate with multiple CEs.
–BGP is designed for passing routing information between systems run by different administrations.
–BGP makes it easy to pass attributes of the routes to the CE.
-VRF-lite does not support IGRP and ISIS.
Reference: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/12-2/31sg/configuration/guide/conf/vrf.html
Q2: The correct answer is B and D, not B and E
VRF-Lite doesnt support IS-IS
I meant Q3*****