HMAC is the standard one with say SHA256. Others may have better performance (you can read about them and their performance in various places). Of course it all depends if your hardware has AES in its CPU, then cipher based MACs can be faster etc.

To start with, see: https://en.wikipedia.org/wiki/Message_authentication_code

Cautionary Note (the reason I have answered here): Now if you are authenticating fixed control signals, and the message is deterministic and the MAC is deterministic as well, you are exposed to simple "repeat attack" you need a protocol level authentication which adds nonces to messages and MAC them all.. 

1- I would use HMAC and suggested in the above answer. You may be able to get away with a hash-based MAC that is weaker, and maybe faster than SHA-256, because in OLSR messages are only valid for a short duration and have an increasing sequence number if I recall correctly 

2- There are other block-ciphers (e.g., Simon and Speck) that are optimized for low-end devices and some of them even towards software only implementations (Speck). You may get better performance out of those if you build a MAC using them.

https://en.wikipedia.org/wiki/Speck_(cipher)https://en.wikipedia.org/wiki/Speck_(cipher)

https://en.wikipedia.org/wiki/Simon_(cipher)

http://csrc.nist.gov/groups/ST/lwc-workshop2015/papers/session1-shors-paper.pdf

Thank you for replies.

I work with inetmanet/omnet++ framework and Cryptopp library (windows).

So I am limited with MAC Cryptopp list! (I can’t use other block-ciphers (e.g., Simon and Speck))

At first,  try more than one algorithm then decide which algorithm is suitable for your work.