ccie lab r&s

Problem：Server 1 can not get ip address.

Materials:

SW3#show ip dhcp snooping  

Switch DHCP snooping is enabled

DHCP snooping is configured on following VLANs:

none

DHCP snooping is operational on following VLANs:

none

Smartlog is configured on following VLANs:

none

Smartlog is operational on following VLANs:

none

DHCP snooping is configured on the following L3 Interfaces:

Insertion of option 82 is enabled

   circuit-id default format: vlan-mod-port

   remote-id: 0018.b9da.5300 (MAC)

Option 82 on untrusted port is not allowed

Verification of hwaddr field is enabled

Verification of giaddr field is enabled

DHCP snooping trust/rate is configured on the following Interfaces:

Interface          Trusted     Allow option     Rate limit (pps)

 --------------------   -------         ------------     ----------------  

Q1：Which material is most helpful

Q2:which packets can help you find the cause

Customer just setup a IPv6 Network, with HSRPv6 on R1 & R2. After setting up, all hosts lose connection.

What would you recommend to your L1 Engineer as a Quick Fix?

CE1 key configuration

standby 1 priority 200

standby 1 preempt

ipv6 nd router-preference low

CE2 key configuration

standby 1 preempt

ipv6 nd router-preference high 

I think it is a rouge device because I don't see any problems with the HSRPv6 config. PCs are configured with "ipv6 enable", "ipv6 autoconfig"

The R1 have a "ipv6 nd-preference high" and R2 have "low" if I'm not wrong.

How fast fix the problem?

¡ Shutdown the link between CE2 and PE2.

¡ Shutdown the link between CE1 and PE1.

¡ Configure CE1 with highest HSRPv6 Priority.

¡ Configure CE2 with highest HSRPv6 pirority.

¡ Configure CE2 with low HSRPv6 priority.

¡ Shutdown CE1 interface e0/0.

¡ Shutdown PE2 interface e0/0.

¡ Disable fast-switching on CE's LAN.

¡ Enable fast-switching on CE's LAN.

¡ Change HSRPv1 to HSRPv2 version