Network : Network > Interfaces : Layer 3 Interface

Layer 3 Interface
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Configure an Ethernet Layer 3 interface to which you can route traffic.
The read-only Interface Name field displays the name of the physical interface you selected.
Select Layer3.
If you want to export unidirectional IP traffic that traverses an ingress interface to a NetFlow server, select the NetFlow profile or select NetFlow Profile to create a new profile (see Device > Server Profiles > NetFlow). Select None to remove the current NetFlow server assignment from the interface.
Assign a virtual router to the interface, or click Virtual Router to define a new one (see Network > Virtual Routers). Select None to remove the current virtual router assignment from the interface.
Assign a logical router to the interface, or click Logical Router to define a new one (see Network > Routing > Logical Routers). Select None to remove the current logical router assignment from the interface.
Select a security zone for the interface or select Zone to define a new zone. Select None to remove the current zone assignment from the interface.
Select Enable SD-WAN to enable SD-WAN functionality for the Ethernet interface.
(PA-220, PA-800, and PA-3200 series only) When you enable this option, the firewall forwards Bonjour multicast advertisements and queries received on and forwarded to this interface to all other L3 and AE interfaces and subinterfaces where you enable this option. This helps ensure user access and device discoverability in network environments that use segmentation to route traffic for security or administrative purposes. You can enable this option on up to 16 interfaces.
Layer3 Interface > IPv4, Type = Static
Add and perform one of the following steps to specify a static IP address and network mask for the interface or AE interface.
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Type the entry in Classless Inter-Domain Routing (CIDR) notation: ip_address/mask (for example, 192.168.2.0/24).
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Create an Address object of type IP netmask.
Delete an IP address when you no longer need it.
If you selected Enable SD-WAN, enter the IPv4 address of the SD-WAN gateway.
Layer3 Interface > IPv4 > General, Type = PPPoE
Select Enable to activate the interface for Point-to-Point Protocol over Ethernet (PPPoE) termination. The interface is a PPPoE termination point to support connectivity in a Digital Subscriber Line (DSL) environment where there is a DSL modem but no other PPPoE device to terminate the connection.
Layer3 Interface > IPv4 > Advanced, Type = PPPoE
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CHAP—Firewall uses Challenge Handshake Authentication Protocol—RFC-1994—on the PPPoE interface.
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PAP—(default) Firewall uses Password Authentication Protocol (PAP) on the PPPoE interface. PAP is less secure than CHAP; PAP sends usernames and passwords in plain text.
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auto—Firewall negotiates the authentication method (CHAP or PAP) with the PPPoE server.
Layer3 Interface > IPv4, Type = DHCP Client
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Select this option to assign a hostname to the DHCP client interface and send that hostname (Option 12) to a DHCP server, which can register the hostname with the DNS server. The DNS server can then automatically manage hostname-to-dynamic IP address resolutions. External hosts can identify the interface by its hostname. The default value indicates system-hostname, which is the firewall hostname that you set in Device > Setup > Management > General Settings. Alternatively, enter a hostname for the interface, which can be a maximum of 64 characters, including uppercase and lowercase letters, numbers, period, hyphen, and underscore.
Layer3 Interface > IPv4, Type = DHCP Client
Select Enable SD-WAN to enable SD-WAN functionality for the Ethernet interface.
Enter the 64-bit extended unique identifier (EUI-64) in hexadecimal format (for example, 00:26:08:FF:FE:DE:4E:29). If you leave this field blank, the firewall uses the EUI-64 generated from the MAC address of the physical interface. If you enable the Use interface ID as host portion option when adding an address, the firewall uses the interface ID as the host portion of that address.
Layer3 Interface > IPv6 > Address Assignment, Type = Static
Select to use the Interface ID as the host portion of the IPv6 address.
Layer3 Interface > IPv6 > Address Assignment, Type = Static
Select to enable router advertisement (RA) for this IP address. (You must also enable the global Enable Router Advertisement option on the interface.) For details on RA, see Enable Router Advertisement in this table. The following fields apply only if you Enable Router Advertisement:
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Valid Lifetime—Length of time, in seconds, that the firewall considers the address valid. The valid lifetime must equal or exceed the Preferred Lifetime. The default is 2,592,000.
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Preferred Lifetime—Length of time, in seconds, that the valid address is preferred, which means the firewall can use it to send and receive traffic. After the preferred lifetime expires, the firewall cannot use the address to establish new connections, but any existing connections are valid until the Valid Lifetime expires. The default is 604,800.
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On-link—Select if systems that have addresses within the prefix are reachable without a router.
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Autonomous—Select if systems can independently create an IP address by combining the advertised prefix with an interface ID.
Layer3 Interface > IPv6 > Address Assignment, Type = DHCPv6 Client
Select the preference of the DHCPv6 Client interface (low, medium, or high) so that, in the event you have two interfaces (each connected to a different ISP for redundancy), you can assign the interface to one ISP a higher preference than the interface to the other ISP. The ISP connected to the preferred interface will be the ISP that provides the delegated prefix to send to a host-facing interface. If the interfaces have the same preference, both ISPs provide a delegated prefix and the host decides which prefix to use.
Layer3 Interface > IPv6 > Address Assignment, Type = DHCPv6 Client > DHCPv6 Options
Fastpath: 
Layer3 Interface > IPv6 > Address Assignment, Type = DHCPv6 Client > Prefix Delegation
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Layer3 Interface > IPv6 > Type = PPPoEv6 Client > General
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CHAP—Interface uses Challenge Handshake Authentication Protocol (CHAP).
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PAP—(default) Interface uses Password Authentication Protocol (PAP). PAP sends usernames and passwords in plain text, and is less secure than CHAP.
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auto—Interface negotiates the authentication method (CHAP or PAP) with the PPPoEv6 server.
Layer3 Interface > IPv6 > Type = PPPoEv6 Client > Address Assignment
Set the preference of the PPPoE client interface: High (default), Medium, or Low. In the event you have two interfaces (each connected to a different ISP for redundancy), you can assign the interface to one ISP a higher preference than the interface to the other ISP. The ISP connected to the preferred interface will be the ISP that provides the delegated prefix to send to a host-facing interface. If the client interfaces have the same preference, both ISPs provide a delegated prefix and the host decides which prefix to use.
Layer3 Interface > IPv6 > Type = PPPoEv6 Client > Address Assignment > Autoconfig
Layer3 Interface > IPv6 > Type = PPPoEv6 Client > Address Assignment > DHCPv6
Layer3 Interface > IPv6 > Type = PPPoEv6 Client > Address Assignment > DHCPv6 > DHCPv6 Options
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DUID-LLT—the Link-Layer address of the interface, concatenated with a timestamp.
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DUID-LL—the Link-Layer address of the interface.
Layer3 Interface > IPv6 > Type = PPPoEv6 Client > Address Assignment > DHCPv6 > Prefix Delegation
If you chose DHCPv6 for address assignment, select Prefix Delegation and Enable Prefix Delegation. This means that the interface accepts a prefix from the upstream DHCPv6 server and places the prefix into the Prefix Pool, from which the firewall delegates a prefix to a host through an RA. The ability to enable or disable prefix delegation for an interface allows the firewall to support multiple ISPs (one ISP per interface). Enabling prefix delegation on this interface controls which ISP provides the prefix. The delegated prefix is used on the host-facing interface, and its IPv6 address is constructed with the MAC address and EUI-64 input.
Layer3 Interface > IPv6 > Address Assignment, Type = Inherited
Add a pool by entering a pool name (a maximum of 63 alphanumeric characters, hyphens, periods, and underscores).
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GUA from Pool—Global Unicast Address (GUA) that comes from the Prefix Pool chosen.
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ULA—Unique Local Address is a private address in the address range fc00::/7 for connectivity within a private network. Select ULA if there is no DHCPv6 server.
Layer3 Interface > IPv6 > Address Assignment, Type = Inherited
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Dynamic—The DHCPv6 Client is responsible for choosing an identifier to configure the inherited interface.
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Dynamic with Identifier—You are responsible for choosing an identifier in the range 0 to 4,000 and maintaining a unique identifier across the DHCPv6 clients.
Layer3 Interface > IPv6 > Address Resolution
Specify the number of DAD attempts within the neighbor solicitation interval (NS Interval) before the attempt to identify neighbors fails (range is 1 to 10; default is 1).
Select to enable Neighbor Discovery Protocol (NDP) monitoring. When enabled, you can select NDP ( in the Features column) to view information about a neighbor the firewall discovered, such as the IPv6 address, the corresponding MAC address, and the User-ID (on a best-case basis).
Layer3 Interface > IPv6 > Router Advertisement, Type = Static or Type = Inherited
This is a global setting for the interface. If you want to set RA options for individual IP addresses, Add and configure an IPv6 address in the IP address table. If you set RA options for any IPv6 address, you must Enable Router Advertisement for the interface.
Layer3 Interface > IPv6 > Router Advertisement, Type = Static or Type = Inherited
Layer3 Interface > IPv6 > Router Advertisement, Type = Static or Type = Inherited
Layer3 Interface > IPv6 > DNS Support, Type = Static
DNS Support is available if you Enable Router Advertisement on the Router Advertisement tab.
Add one or more recursive DNS (RDNS) server addresses for the firewall to send in NDP router advertisements from this IPv6 Ethernet interface. RDNS servers send a series of DNS look up requests to root DNS and authoritative DNS servers to ultimately provide an IP address to the DNS client.
Layer3 Interface > IPv6 > DNS Support, Type = Static
Layer3 Interface > IPv6 > DNS Support
Add one or more domain names (suffixes) for the DNS search list (DNSSL). Maximum length is 255 bytes.
Layer3 Interface > IPv6 > DNS Support, Type = DHCPv6 Client, PPPoEv6 Client,or Inherited
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DHCPv6—To have the DHCPv6 Server send the DNS Recursive Name Server information.
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Manual—To manually configure the DNS Recursive Name Server.
If you choose Manual, Add the IPv6 address of a recursive DNS (RDNS) Server (for example, 2001:4860:4860:0:0:8888) for the firewall to send in NDP router advertisements from this IPv6 VLAN interface. RDNS servers send a series of DNS lookup requests to root DNS servers and authoritative DNS servers to ultimately provide an IP address to the DNS client.
You can configure a maximum of eight RDNS servers that the firewall sends— in the order listed from top to bottom—in an NDP router advertisement to the recipient, which then uses them in the same order. Select a server and Move Up or Move Down to change the order of the servers or Delete a server from the list when you no longer need it. Enter a Lifetime in seconds, which is the maximum length of time the client can use the specific RDNS server to resolve domain names. Range is 4 to 3,600; default is 1,200.
Layer3 Interface > IPv6 > DNS Support, Type = DHCPv6 Client, PPPoEv6 Client, or Inherited
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DHCPv6—To have the DHCPv6 Server send the Domain Search List information.
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Manual—To manually configure the Domain Search List.
If you choose Manual, Add and configure one or more Domain names (suffixes) for the DNS search list (DNSSL). The maximum suffix length is 255 bytes.
Enter a Lifetime in seconds, which is the maximum length of time the client can use the specific Domain Search List. Range is 4 to 3,600; default is 1,200.
If you selected Enable SD-WAN on the IPv4 tab, the firewall indicates SD-WAN Interface Status: Enabled. If you didn’t Enable SD-WAN, it indicates Disabled.
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You must Enable SD-WAN for the interface before you can apply an SD-WAN Interface Profile.
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Static IP—Select the Type to be IP Address or FQDN and enter the IPv4 address or FQDN.
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DDNS—Dynamic DNS (DDNS) derives the IP address of the upstream NAT device.
Ethernet Interface > Advanced > Link Settings
Select the interface speed in Mbps, or select auto to have the firewall automatically determine the speed.
Select whether the interface transmission mode is full-duplex (full), half-duplex (half), or negotiated automatically (auto).
Select whether the interface status is enabled (up), disabled (down), or determined automatically (auto).
Ethernet Interface > Advanced > PoE Settings
(Supported firewalls only)
Layer3 Interface > Advanced > Other Info
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IPv4 MSS Adjustment Size—Range is 40 to 300; default is 40.
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IPv6 MSS Adjustment Size—Range is 60 to 300; default is 60.
Use these settings to address the case where a tunnel through the network requires a smaller MSS. If a packet has more bytes than the MSS without fragmentation, this setting enables the adjustment.
Layer3 Interface > Advanced > ARP Entries
To add one or more static Address Resolution Protocol (ARP) entries, Add an IP address and its associated hardware [media access control (MAC)] address. To delete an entry, select the entry and click Delete. Static ARP entries reduce ARP processing.
Layer3 Interface > Advanced > ND Entries
To provide neighbor information for Neighbor Discovery Protocol (NDP), Add the IPv6 address and MAC address of the neighbor.
Layer3 Interface > Advanced > NDP Proxy
If you selected Enable NDP Proxy, you can filter numerous Address entries by entering a filter and clicking Apply Filter (gray arrow).
Add one or more IPv6 addresses, IP ranges, IPv6 subnets, or address objects for which the firewall will act as NDP proxy. Ideally, one of these addresses is the same address as that of the source translation in NPTv6. The order of addresses does not matter.
Negate an address to prevent NDP proxy for that address. You can negate a subset of the specified IP address range or IP subnet.
Layer3 Interface > Advanced > LLDP
Select an LLDP Profile or create a new LLDP Profile. The profile is the way in which you configure the LLDP mode, enable syslog and SNMP notifications, and configure the optional Type-Length-Values (TLVs) you want transmitted to LLDP peers.
Layer3 Interface > Advanced > DDNS
Select Settings to make the DDNS fields available to configure.
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Create a Certificate Profile to verify the DDNS service. The DDNS service presents the firewall with a certificate signed by the certificate authority (CA).
Layer3 Interface > Advanced > DDNS
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Palo Alto Networks DDNS (applies to SD-WAN Full Mesh with DDNS, SD-WAN AE subinterfaces and SD-WAN Layer 3 subinterfaces)
The Name and Value fields that follow the vendor name are vendor-specific. The read-only fields notify you of parameters that the firewall uses to connect to the DDNS service. Configure the other fields, such as a password that the DDNS service provides to you and a timeout that the firewall uses if it doesn’t receive a response from the DDNS server.
Network > Interfaces