Web Management Guide-R06
Table Of Contents
- How to Use This Guide
- Contents
- Figures
- Tables
- Getting Started
- Web Configuration
- Using the Web Interface
- Basic Management Tasks
- Displaying System Information
- Displaying Hardware/Software Versions
- Configuring Support for Jumbo Frames
- Displaying Bridge Extension Capabilities
- Managing System Files
- Setting the System Clock
- Configuring the Console Port
- Configuring Telnet Settings
- Displaying CPU Utilization
- Displaying Memory Utilization
- Stacking
- Resetting the System
- Interface Configuration
- VLAN Configuration
- Address Table Settings
- Spanning Tree Algorithm
- Congestion Control
- Class of Service
- Quality of Service
- VoIP Traffic Configuration
- Security Measures
- AAA (Authentication, Authorization and Accounting)
- Configuring User Accounts
- Web Authentication
- Network Access (MAC Address Authentication)
- Configuring HTTPS
- Configuring the Secure Shell
- Access Control Lists
- Setting a Time Range
- Showing TCAM Utilization
- Setting the ACL Name and Type
- Configuring a Standard IPv4 ACL
- Configuring an Extended IPv4 ACL
- Configuring a Standard IPv6 ACL
- Configuring an Extended IPv6 ACL
- Configuring a MAC ACL
- Configuring an ARP ACL
- Binding a Port to an Access Control List
- Configuring ACL Mirroring
- Showing ACL Hardware Counters
- ARP Inspection
- Filtering IP Addresses for Management Access
- Configuring Port Security
- Configuring 802.1X Port Authentication
- DoS Protection
- IPv4 Source Guard
- IPv6 Source Guard
- DHCP Snooping
- Basic Administration Protocols
- Configuring Event Logging
- Link Layer Discovery Protocol
- Power over Ethernet
- Simple Network Management Protocol
- Configuring Global Settings for SNMP
- Setting the Local Engine ID
- Specifying a Remote Engine ID
- Setting SNMPv3 Views
- Configuring SNMPv3 Groups
- Setting Community Access Strings
- Configuring Local SNMPv3 Users
- Configuring Remote SNMPv3 Users
- Specifying Trap Managers
- Creating SNMP Notification Logs
- Showing SNMP Statistics
- Remote Monitoring
- Switch Clustering
- Ethernet Ring Protection Switching
- Connectivity Fault Management
- Configuring Global Settings for CFM
- Configuring Interfaces for CFM
- Configuring CFM Maintenance Domains
- Configuring CFM Maintenance Associations
- Configuring Maintenance End Points
- Configuring Remote Maintenance End Points
- Transmitting Link Trace Messages
- Transmitting Loop Back Messages
- Transmitting Delay-Measure Requests
- Displaying Local MEPs
- Displaying Details for Local MEPs
- Displaying Local MIPs
- Displaying Remote MEPs
- Displaying Details for Remote MEPs
- Displaying the Link Trace Cache
- Displaying Fault Notification Settings
- Displaying Continuity Check Errors
- OAM Configuration
- UDLD Configuration
- Multicast Filtering
- Overview
- Layer 2 IGMP (Snooping and Query for IPv4)
- Configuring IGMP Snooping and Query Parameters
- Specifying Static Interfaces for a Multicast Router
- Assigning Interfaces to Multicast Services
- Setting IGMP Snooping Status per Interface
- Filtering IGMP Query Packets and Multicast Data
- Displaying Multicast Groups Discovered by IGMP Snooping
- Displaying IGMP Snooping Statistics
- Filtering and Throttling IGMP Groups
- MLD Snooping (Snooping and Query for IPv6)
- Layer 3 IGMP (Query used with Multicast Routing)
- Multicast VLAN Registration for IPv4
- Multicast VLAN Registration for IPv6
- IP Configuration
- IP Services
- General IP Routing
- Configuring Router Redundancy
- Unicast Routing
- Overview
- Configuring the Routing Information Protocol
- Configuring General Protocol Settings
- Clearing Entries from the Routing Table
- Specifying Network Interfaces
- Specifying Passive Interfaces
- Specifying Static Neighbors
- Configuring Route Redistribution
- Specifying an Administrative Distance
- Configuring Network Interfaces for RIP
- Displaying RIP Interface Settings
- Displaying Peer Router Information
- Resetting RIP Statistics
- Configuring the Open Shortest Path First Protocol (Version 2)
- Defining Network Areas Based on Addresses
- Configuring General Protocol Settings
- Displaying Administrative Settings and Statistics
- Adding an NSSA or Stub
- Configuring NSSA Settings
- Configuring Stub Settings
- Displaying Information on NSSA and Stub Areas
- Configuring Area Ranges (Route Summarization for ABRs)
- Redistributing External Routes
- Configuring Summary Addresses (for External AS Routes)
- Configuring OSPF Interfaces
- Configuring Virtual Links
- Displaying Link State Database Information
- Displaying Information on Neighboring Routers
- Multicast Routing
- Appendices
- Glossary
- Index
Chapter 17
| General IP Routing
Address Resolution Protocol
– 682 –
Address Resolution Protocol
If IP routing is enabled (page 703), the router uses its routing tables to make routing
decisions, and uses Address Resolution Protocol (ARP) to forward traffic from one
hop to the next. ARP is used to map an IP address to a physical layer (i.e., MAC)
address. When an IP frame is received by this router (or any standards-based
router), it first looks up the MAC address corresponding to the destination IP
address in the ARP cache. If the address is found, the router writes the MAC address
into the appropriate field in the frame header, and forwards the frame on to the
next hop. IP traffic passes along the path to its final destination in this way, with
each routing device mapping the destination IP address to the MAC address of the
next hop toward the recipient, until the packet is delivered to the final destination.
If there is no entry for an IP address in the ARP cache, the router will broadcast an
ARP request packet to all devices on the network. The ARP request contains the
following fields similar to that shown in this example:
When devices receive this request, they discard it if their address does not match
the destination IP address in the message. However, if it does match, they write
their own hardware address into the destination MAC address field and send the
message back to the source hardware address. When the source device receives a
reply, it writes the destination IP address and corresponding MAC address into its
cache, and forwards the IP traffic on to the next hop. As long as this entry has not
timed out, the router will be able forward traffic directly to the next hop for this
destination without having to broadcast another ARP request.
Also, if the switch receives a request for its own IP address, it will send back a
response, and also cache the MAC of the source device's IP address.
Basic ARP
Configuration
Use the IP > ARP (Configure General) page to specify the timeout for ARP cache
entries, or to enable Proxy ARP for specific VLAN interfaces.
Command Usage
Proxy ARP
When a node in the attached subnetwork does not have routing or a default
gateway
configured, Proxy ARP can be used to forward ARP requests to a remote
subnetwork.
When the router receives an ARP request for a remote network and
Proxy ARP is enabled, it determines if it has the best route to the remote network,
and then answers the ARP request by sending its own MAC address to the
Table 41: Address Resolution Protocol
destination IP address 10.1.0.19
destination MAC address ?
source IP address 10.1.0.253
source MAC address 00-00-ab-cd-00-00