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carl_t
Contributor

Proxy arps

Hi Guys

Can anyone tell me when we need to use proxy arps?

If I have a manual NAT rule with hide NAT, but the NAT object is on the same IP range as the outside interface, do I need to use proxy arp?

cheers

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2 Replies
G_W_Albrecht
MVP Silver
MVP Silver

See sk30197 about when you need it. Symptoms are:

- After creating a Manual Static NAT rule, Security Gateway does not answer the ARP Requests for the Static NATed IP address that was configured in the Manual NAT rule.

- Security Gateway replies to ARP requests with a wrong MAC address, mostly for the NAT traffic.

sk30197: Configuring Proxy ARP for Manual NAT

sk114395: Automatic creation of Proxy ARP for Manual NAT rules on Security Gateway

CCSP - CCSE / CCTE / CTPS / CCME / CCSM Elite / SMB Specialist
Chris_Atkinson
MVP Platinum CHKP MVP Platinum CHKP
MVP Platinum CHKP

This is the general situation where the gateway would need to be doing proxy-arp correct.

By comparison if the IP addresses were statically routed towards the Gateway as part of a different subnet this isn't necessary.

CCSM R77/R80/ELITE

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