Mac Pinning - ZyXEL Communications GS3700 Series User Manual

This chapt er shows you how t o configure MAC pinning on t he Swit ch.
32.1 MAC Pinning Overview
When t he Swit ch obt ains a connect ed device's MAC address, it adds an ent ry in t he MAC address
forwarding t able and uses t he t able t o det erm ine how t o forward fram es. I n addit ion t o t he source
MAC address of a received fram e, t he Swit ch also learns t he VLAN t o which t he device belongs and
t he port on which t he fram e is received. I f t he Swit ch learns t he sam e MAC address and sam e VLAN
I D on anot her port , it updat es t he MAC address t able im m ediat ely.
MAC pinning allows you t o set a port or m ult iple port s t o have priorit y over ot her port s in MAC
address learning. That m eans when a MAC address ( and VLAN I D) is learned on a MAC- pinning-
enabled port , t he MAC address will not be learned on any ot her port unt il t he aging t im e for t he
dynam ically learned MAC address in t he t able expires.
This helps enhance securit y. For exam ple, when an at t acker ( A) sends packet s t o all connect ed
client s by spoofing t he source MAC address of a server ( B) connect ed t o one of t he Swit ch's port s,
on which MAC pinning is enabled, t he responses from client s will st ill be forwarded t o t he server
according t o t he Swit ch's MAC forwarding t able.
[MAC x, VLAN y]
32.2 MAC Pinning Configuration
Use t his screen t o enable MAC pinning on t he Swit ch and on specific port s. Click Adva nce d
Applica t ion > M AC Pin n in g in t he navigat ion panel t o open t he following screen.
B
GS3700/XGS3700 Series User's Guide
C
HAPTER

MAC Pinning

A
[MAC x, VLAN y]
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