Dagr banner saga

ARP is disabled by default; this task describes how to enable local proxy ARP. SUMMARY STEPS configure interface type number local-proxy-arp commit DETAILED STEPS Command or Action Purpose Step 1 configure Step 2 interface type number Example: RP/0/RSP0/CPU0:router(config)# interface TenGigE 0/0/0/0 Enters interface configuration mode. Step 3 local-proxy-arp Example: RP/0/RSP0/CPU0:router(config-if)# local-proxy-arp Enables local proxy ARP on the interface. Step 4 commit Configuring DAGR Follow these steps to create a DAGR group on the Cisco ASR 9000 Series Router. SUMMARY STEPS configure interface type interface-path-id arp dagr peer ipv4 address route distance normal normal- distance priority priority-distance route metric normal normal- metric priority priority-metric timers query query-time standby standby-time priority-timeout time Do one of the following: end commit show arp dagr [ interface [ IP-address ]] DETAILED STEPS Command or Action Purpose Step 1 configure Example: RP/0/RSP0/CPU0:router# configure Enters global configuration mode. Step 2 interface type interface-path-id Example: RP/0/RSP0/CPU0:router(config)# interface gigabitethernet 0/2/0/0 Enters interface configuration mode and configures an interface. Step 3 arp dagr Example: RP/0/RSP0/CPU0:router(config-if)# arp dagr Enters DAGR configuration mode. Step 4 peer ipv4 address Example: RP/0/RSP0/CPU0:router(config-if-dagr)# peer ipv4 10.0.0.100 Creates a new DAGR group for the virtual IP address. Step 5 route distance normal normal- distance priority priority-distance Example: RP/0/RSP0/CPU0:router(config-if-dagr-peer)# route distance normal 140 priority 3 (Optional) Configures route distance for the DAGR group. Step 6 route metric normal normal- metric priority priority-metric Example: RP/0/RSP0/CPU0:router(config-if-dagr-peer)# route metric normal 84 priority 80 (Optional) Configures the route metric for the DAGR group. Step 7 timers query query-time standby standby-time Example: RP/0/RSP0/CPU0:router(config-if-dagr-peer)# timers query 2 standby 19 (Optional) Configures the time in seconds between successive ARP requests being sent out for the virtual IP address. Step 8 priority-timeout time Example: RP/0/RSP0/CPU0:router(config-if-dagr-peer)# priority-timeout 25 (Optional) Configures a timer for the length of time in seconds to wait before reverting to normal priority from a high-priority DAGR route. Step 9 Do one of the following: end commit Example: RP/0/RSP0/CPU0:router(config-if-dagr)# end or RP/0/RSP0/CPU0:router(config-if-dagr)# commit Saves configuration changes. When you issue the end command, the system prompts you to commit changes: Uncommitted changes found, commit them before exiting(yes/no/cancel)?[cancel]: Entering yes saves configuration changes to the running configuration file, exits the configuration session, and returns the router to EXEC mode. Entering no exits the configuration session and returns the router to EXEC mode without committing the configuration changes. Entering cancel leaves the router in the current configuration session without exiting or committing the configuration changes. Use

In scale improves performance while multiple ARP operations are being processed on the device. Direct Attached Gateway Redundancy Direct Attached Gateway Redundancy (DAGR) allows third-party redundancy schemes on connected devices to use gratuitous ARP as a failover signal, enabling the ARP process to advertise an new type of route in the Routing Information Base (RIB). These routes are distributed by Open Shortest Path First (OSPF). Sometimes part of an IP network requires redundancy without routing protocols. A prime example is in the mobile environment, where devices such as base station controllers and multimedia gateways are deployed in redundant pairs, with aggressive failover requirements (subsecond or less), but typically do not have the capability to use native Layer 3 protocols such as OSPF or Intermediate System-to-Intermediate System (IS-IS) protocol to manage this redundancy. Instead, these devices assume they are connected to adjacent IP devices over an Ethernet switch, and manage their redundancy at Layer 2, using proprietary mechanisms similar to Virtual Router Redundancy Protocol (VRRP). This requires a resilient Ethernet switching capability, and depends on mechanisms such as MAC learning and MAC flooding. DAGR is a feature that enables many of these devices to connect directly to Cisco ASR 9000 Series Routers without an intervening Ethernet switch. DAGR enables the subsecond failover requirements to be met using a Layer 3 solution. No MAC learning, flooding, or switching is required. Note Since mobile devices' 1:1 Layer 2 redundancy mechanisms are proprietary, they do not necessarily conform to any standard. So although most IP mobile equipment is compatible with DAGR, interoperability does require qualification, due to the possibly proprietary nature of the Layer 2 mechanisms with which DAGR interfaces. Additional Guidelines The following are additional guidelines to consider when configuring DAGR: Up to 40 DAGR peers, which may be on the same or different interfaces, are supported per system. Failover is supported for DAGR routes within 500 ms of receipt of an ARP reply packet. On ARP process restart, DAGR groups are reinitialized. How to Configure ARP This section contains instructions for the following tasks: Defining a Static ARP Cache Entry ARP and other address resolution protocols provide a dynamic mapping between IP addresses and media addresses. Because most hosts support dynamic address resolution, generally you need not to specify static ARP cache entries. If you must define them, you can do so globally. Performing this task installs a permanent entry in the

Do show arp traffic gigabitEthernet 0/1/0/0 location 0/1/CPU0Mon Nov 26 14:08:34.403 ISTARP statistics: Recv: 0 requests, 0 replies (0 unsolicited) Sent: 5 requests, 1 replies (0 proxy, 0 local proxy, 1 gratuitous) Subscriber Interface: 0 requests recv, 0 replies sent, 0 gratuitous replies sent Resolve requests rcvd: 1 Resolve requests dropped: 0 Errors: 0 out of memory, 0 no buffers, 0 out of sunbetARP cache: Total ARP entries in cache: 2 Dynamic: 0, Interface: 1, Standby: 0 Alias: 0, Static: 0, DHCP: 0, DropAdj: 1 IP Packet drop count for GigabitEthernet0_1_0_0: 1 Configuration Examples for ARP Configuration on Cisco IOS XR Software This section provides the following ARP configuration examples: Creating a Static ARP Cache Entry: Example The following is an example of a static ARP entry for a typical Ethernet host: configurearp 192.168.7.19 0800.0900.1834 arpa The following is an example of a static ARP entry for a typical Ethernet host where the software responds to ARP requests as if it were the owner of both the specified IP address and hardware address, whether proxy ARP is enabled or not: configurearp 192.168.7.19 0800.0900.1834 arpa alias The following is an example of configuring a static arp entry on an SRP device: configurearp 192.168.8.20 0800.0900.1723 srp Enabling Proxy ARP: Example The following is an example of enabling proxy ARP: configureinterface MgmtEth 0/RSP0/CPU0/0proxy-arp Displaying the ARP Table: Example The following example shows how to display the ARP table: Router# show arp------------------------------------------------------------------------------0/1/CPU0------------------------------------------------------------------------------Address Age Hardware Addr State Type Interface1.1.1.1 - 027d.42e9.bd36 Interface ARPA GigabitEthernet0/1/0/01.1.1.2 00:00:06 0000.0000.0000 DropAdj ARPA GigabitEthernet0/1/0/0 Enabling DAGR and Configuring a DAGR Group: Example The following is an example of enabling DAGR and configuring a DAGR group peer: configure interface gigabitethernet 0/1/0/0.1 arp dagr peer ipv4 192.168.7.19 priority-timeout 25 route distance normal 48 priority 5 route metric normal 48 priority 5 timers query 2 standby 40 commit Displaying the Operational State of DAGR Groups: Example The following example shows how to display the current operational state of the DAGR groups: RP/0/RSP0/CPU0:router# show arp dagr--------------------------------------------------------------------------------0/1/CPU0--------------------------------------------------------------------------------Interface Virtual IP State Query-pd Dist MetrGigabitEthernet0/1/0/2 10.168.7.19 Active None 150 100GigabitEthernet0/1/0/2 10.24.0.45 Query 1 None NoneGigabitEtherget0/1/0/3 10.66.0.45 Init None None None ARP Throttling When remote devices scan for destinations that do not exist in the locally connected network, the packets with unresolved ARP requests causes continuous queue of ARP packets pending for resolution. Failed ARP resolution entries impacts forwarding and performance of the router because CPU cycles are