An engineer is designing a load balancing solution for two Cisco Unified Border Element routers.
The first router (cube1.abc.com) takes 60% of the calls and the second router (cube2.abc.com) takes 40% of the calls.
Assume all DNS A records have been created.
Which two SRV records are needed for a load balanced solution? (Choose two.)
Click on the arrows to vote for the correct answer
A. B. C. D. E.CE.
When load balancing two Cisco Unified Border Element (CUBE) routers, DNS SRV records are used to distribute incoming calls across both routers. SRV records provide the ability to define the weight, priority, and port for each CUBE router.
In this case, the first router (cube1.abc.com) takes 60% of the calls, and the second router (cube2.abc.com) takes 40% of the calls. We need to create two SRV records for the abc.com domain to load balance the traffic between the two CUBE routers.
The format for the SRV record is as follows: _Service.Proto.Name TTL Class SRV Priority Weight Port Target
Where:
_Service is the service being offered. In this case, it is SIP, so the value would be _sip.
_Proto is the protocol used to provide the service. In this case, it is UDP, so the value would be _udp.
_Name is the domain name associated with the service. In this case, it is abc.com.
TTL is the time-to-live for the record.
Class is the DNS class of the record.
SRV is the record type.
Priority is the priority of the target host, with lower numbers indicating higher priority.
Weight is the relative weight for records with the same priority, with higher numbers indicating higher weight.
Port is the TCP or UDP port number on which the service is provided.
Target is the domain name of the target host.
With this information in mind, let's analyze each answer choice:
A. _sip._udp.abc.com 60 IN SRV 2 60 5060 cube1.abc.com This answer sets the priority to 2, weight to 60, and the target to cube1.abc.com. The weight indicates the percentage of calls that will be directed to cube1.abc.com, which is set to 60. However, the priority is incorrect. The priority value should be lower for the host that should handle the requests first.
B. _sip._udp.abc.com 60 IN SRV 60 1 5060 cube1.abc.com This answer sets the priority to 60, weight to 1, and the target to cube1.abc.com. This configuration is incorrect since a priority of 60 is too high. The priority number should start from 0 or 1 for the host that should handle requests first.
C. _sip._udp.abc.com 60 IN SRV 1 40 5060 cube2.abc.com This answer sets the priority to 1, weight to 40, and the target to cube2.abc.com. This configuration is correct since it sets the priority for the router that should handle the requests first.
D. _sip._udp.abc.com 60 IN SRV 3 60 5060 cube2.abc.com This answer sets the priority to 3, weight to 60, and the target to cube2.abc.com. This configuration is incorrect since the priority value should be lower for the host that should handle requests first.
E. _sip._udp.abc.com 60 IN SRV 1 60 5060 cube1.abc.com This answer sets the priority to 1, weight to 60, and the target to cube1.abc.com. This configuration is correct since it sets the priority for the router that should handle the requests first and distributes 60% of the calls to it.
Therefore, the correct answers are C and E. The SRV records to load balance the traffic between two CUBE routers for abc.com domain would be:
sip.