IP Phone ARP Broadcast

[singhaam007]

HI there,

I was doing wire shark on one of the machine coz of one slow network performance issue and got many ARP Broadcast messages.

Broadcast    Arp    60 who has x.x.31.1 Tell x.x.31.71

Broadcast    Arp    60 who has x.x.31.1 Tell x.x.31.76

Broadcast    Arp    60 who has x.x.31.1 Tell x.x.31.11

Broadcast    Arp    60 who has x.x.31.1 Tell x.x.31.31

Broadcast    Arp    60 who has x.x.31.1 Tell x.x.31.46

Broadcast    Arp    60 who has x.x.31.1 Tell x.x.31.20

Broadcast    Arp    60 who has x.x.31.1 Tell x.x.31.71

Broadcast    Arp    60 who has x.x.31.1 Tell x.x.31.80

Half of the traffic is broadcast.

Is it normal switch behavior? It is a 2960 Cisco with 12(55)

Any body knows why we are getting so many arp requests for the default gateway from all of these phones.

thanks

[paolo bevilacqua]

They need to reach IPs beyond the local subnet. That is normal and does not cause any problem now slowness.

[singhaam007]

Hi Paolo,

thanks so much for your reply.

Pretty much half of the traffic is broadcast when I ever I do wire shark capture on one user interface. Like if I capture 1000 packets the 500 will be broadcast packets.

Just wondering if these excessive broadcast packet causing any issue.

thanks

[paolo bevilacqua]

As above, no issue really.