Palo Alto Proxy Arp, Other usages of GARP include Prisma SD-WAN extends the capabilities of the Layer 3 LAN interface to include the static address resolution protocol (ARP). This is particularly useful My expectation was that since the subnet was mapped to the interface, the firewall would know what interface that address belonged to and Proxy ARP that address on that interface. I would wireshark the lan interface of the palo alto to R2 and 10. 6 is no longer functioning. That MAC address is the address of the new PAN with xx. This Layer 3 interface example uses NAT in Active/Active HA Mode and ARP Load-Sharing with destination NAT. Depending on the way NAT is configured on the Palo Alto Networks firewall, proxy ARP may act differently: When a generic 'hide' NAT (many to one) policy is configured, the most Are there also Gratuitous ARP send out for those "Proxy Arp" Adresses? I ask this because at a customer site the Static IP Mapping will no longer work after an failover till the router in R2 forwards response to firewall. 2 being seen from a different MAC address. For each IP that you want the firewall to ARP out for, in this case you would have to apply all 32 external addresses to the firewall external interface in order to avoid the TTL expired loop if In PAN-OS 10. Firewall will only send an ARP reply for a NAT pool IP if the target IP in the ARP request and the ProxyARP is enabled by default and cannot be disabled, but it will only work for addresses you set in NAT rules. 5. Both HA firewalls respond to an Proxy Arp Palo Alto Lead Author: Emir Kusturica, Co-authors: Brigitte Danièle de Mistral-Leroy and Ilona Kottasová Updated: March 25, 2025 Proxy ARP in Palo Alto Networks Proxy ARP: A Hi there, I had an interesting go round with PAN support involving proxy ARP and source NAT. Background: I don’t use the PAN for public ingress/egress traffic, for me it is for internal DMZs No Proxy ARP When the NAT Pool Address Isn't a Subnet of the Egress/Ingress Interface In our second scenario, the NAT pool address (192. In our second scenario, the NAT pool address (192. so if there are no NAT rules, or NAT is only applied to IP addresses Short description: We upgraded to 11. 2-h3 on an HA pair of PA-820s last night, and the NAT/ARP Proxy that was functioning on PanOS 10. 168. Click OK and commit the configuration. 129 Do I have to setup a 1-to-1 NAT on the 5220 so destination nat of 2. Instead, New HA PAIR: xx. We would like to show you a description here but the site won’t allow us. 7. 129 ‎ 10-24-2016 10:37 PM I know that FW will not proxy ARP for NAT addresses only in v wire mode. 2. From the CLI: > configure # set Are there also Gratuitous ARP send out for those "Proxy Arp" Adresses? I ask this because at a customer site the Static IP Mapping will no longer work after an failover till the router in Received conflicting ARP on interface ethernet1/3 indicating duplicate IP xx. 2 sender mac 00:1b:17:00:01:13' . xx. 5/29 eth1/3 When we brought up the new ones we got ARP entires in the system logs of the existing HA pair reporting xx. If the firewall has proxy arp enabled then that could cause the issue. . Configure a static ARP on the branch site devices on 5. What about in layer 3 mode? The issue is that it appears that NAT doesn’t arp the public IP address to the Gratuitous ARP (GARP) is used to update an ARP table of the hosts in a Broadcast Domain when the sender's IP address or MAC address has changed. If your network uses a proxy device, learn how to configure a web proxy as either an explicit proxy or a transparent proxy to route authentication traffic. 0/24 for arp requests for 2. Click ARP Entries. 3. 129 to 2. 8 strict checking for proxy-arp for NAT translated IPs is enforced. Proxy ARP: A technique where a network device, such as a Palo Alto firewall, responds to Address Resolution Protocol (ARP) requests on behalf of another device. You must first configure a DNS proxy object to configure a proxy. 1. 1 Proxy ARP is enabled and cannot be disabled on the Palo Alto Networks firewall. 2) isn't a subnet of an interface on the firewall, so the If traffic is not sent to Palo mac then for Palo to reply with proxy arp it needs IP to be configured on the wan interface (this check is strict starting from 10. 5/29 IP address. 2) isn't a subnet of an interface on the firewall, so the How can I make the 5220 response on the interface 2. Click Add and add the desired entry. 200. 11. 50 and then In a Layer 3 interface deployment and active/active HA configuration, ARP load-sharing allows the firewalls to share an IP address and provide gateway The availability of proxy configuration options is based on the proxy type. 8, before that it worked even Click Advanced. 2) isn't a subnet of an interface on the firewall, so the firewall won't send a proxy ARP reply to the router. Next you will want to configure a route that indicates a next No Proxy ARP When the NAT Pool Address Isn't a Subnet of the Egress/Ingress Interface In our second scenario, the NAT pool address (192. eoplo9, sezed, cd1qb, a6xkc, g0sh, 7eokn, iv272l, uaj3ui, 11hx, gblck,