Identify the reason causing the issue.

Scenario:
You have been asked by your customer to help resolve issues in their routed network. Their
network engineer has deployed HSRP. On closer inspection HSRP doesn’t appear to be operating
properly and it appears there are other network problems as well. You are to provide solutions to
all the network problems.

The following debug messages are noticed for HSRP group 2. But still neither R1 nor
R2 has identified one of them as standby router. Identify the reason causing the
issue.
Note: only show commands can be used to troubleshoot the ticket.
R1#
‘Mar 26 11:17:39.234: HSRP: Et1/0 Grp 2 Hello out 172.16.20.2 Active pri 100 vIP
172.16.20.254
‘Mar 26 11:17:40.034: HSRP: EtO/0 Grp 1 Hello out 172.16.10.2 Active prj 130 vIP
172.16.10.254
R1#
‘Mar 26 11:17:40.364: HSRP: EtO/0 Grp 1 Hello in 172.16.10.1 Standby pri 100 vIP
172.16.10.254
R1#
‘Mar 26 11:17:41.969: HSRP: Et1/0 Grp 2 Hello out 172.16.20.2 Active pri 100 vIP
172.16.20.254

‘Mar 26 11:17:42.719: HSRP: EtO/0 Grp 1 Hello out 172.16.10.2 Active prj 130 vIP
172.16.10.254
‘Mar 26 11:17:42.918: HSRP: EtO/0 Grp 1 Hello in 172.16.10.1 Standby pri 100 vIP
172.16.10.254
R1#
‘Mar 26 11:17:44.869: HSRP: Et1/0 Grp 2 Hello out 172.16.20.2 Active pri 100 vIP
172.16.20.254
‘Mar 26 11:17:45.485: HSRP: EtO/0 Grp 1 Hello out 172.16.10.2 Active prj 130 vIP
172.16.10.254
‘Mar 26 11:17:45.718: HSRP: EtO/0 Grp 1 Hello in 172.16.10.1 Standby pri 100 vIP
172.16.10.254
R1#
‘Mar 26 11:17:47.439: HSRP: Et1/0 Grp 2 Hello out 172.16.20.2 Active pri 100 vIP
172.16.20.254
‘Mar 26 11:17:48.252: HSRP: EtO/0 Grp 1 Hello in 172.16.10.1 Standby pri 100 vIP
172.16.10.254
‘Mar 26 11:17:48.322: HSRP: EtO/0 Grp 1 Hello out 172.16.10.2 Active prj 130 vIP
172.16.10.254
R1#
‘Mar 26 11:17:50.389: HSRP: Et1/0 Grp 2 Hello out 172.16.20.2 Active pri 100 vIP
172.16.20.254
‘Mar 26 11:17:50.735: HSRP: EtO/0 Grp 1 Hello in 172.16.10.1 Standby pri 100 vIP
172.16.10.254
‘Mar 26 11:17:50.921: HSRP: EtO/0 Grp 1 Hello out 172.16.10.2 Active prj 130 vIP
172.16.10.254
R1#
‘Mar 26 11:17:53.089: HSRP: Et1/0 Grp2 Hello out 172.16.20.2 Active pri 100 vIP

172.16.20.254
‘Mar 26 11:17:53.338: HSRP: EtO/0 Grp 1 Hello out 172.16.10.2 Active pri130vlP
172.16.10.254
‘Mar 26 11:17:53.633: HSRP: EtO/0 Grp 1 Hello in 172.16.10.1 Standby pri 100 vIP
172.16.10.254

A.
HSRP group priority misconfiguration

B.
There is an HSRP authentication misconfiguration

C.
There is an HSRP group number mismatch

D.
This is not an HSRP issue: this is DHCP issue.

E.
The ACL applied to interface is blocking HSRP hello packet exchange

Explanation:
On R1 we see that access list 102 has been applied to the Ethernet 1/0 interface:

This access list is blocking all traffic to the 224.0.0.102 IP address, which is the multicast address
used by HSRP.