Web Management Guide
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
- Resetting the System
- Interface Configuration
- VLAN Configuration
- Address Table Settings
- Spanning Tree Algorithm
- Congestion Control
- Class of Service
- Layer 2 Queue Settings
- Layer 3/4 Priority Settings
- Setting Priority Processing to IP Precedence/DSCP or CoS
- Mapping Ingress DSCP Values to Internal DSCP Values
- Mapping CoS Priorities to Internal DSCP Values
- Mapping Internal DSCP Values to Egress CoS Values
- Mapping IP Precedence Values to Internal DSCP Values
- Mapping IP Port Priority to Internal DSCP Values
- Quality of Service
- 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
- 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
- IPv4 Source Guard
- IPv6 Source Guard
- DHCP Snooping
- Basic Administration Protocols
- Configuring Event Logging
- Link Layer Discovery Protocol
- 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
- 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
- UDLD Configuration
- Multicast Filtering
- Overview
- IGMP Protocol
- Layer 2 IGMP (Snooping and Query for IPv4)
- Configuring IGMP Snooping and Query Parameters
- Specifying Static Interfaces for an IPv4 Multicast Router
- Assigning Interfaces to IPv4 Multicast Services
- Setting IGMP Snooping Status per Interface
- Filtering IGMP Query Packets
- 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)
- IP Configuration
- IP Services
- General IP Routing
- 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
- Specifying Passive Interfaces
- Multicast Routing
- Appendices
- Glossary
- Index
Chapter 16
| General IP Routing
Address Resolution Protocol
– 522 –
Address Resolution Protocol
If IP routing is enabled (page 543), 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.
ARP Timeout
Configuration
Use the IP > ARP (Configure General) page to specify the timeout for ARP cache
entries.
Parameters
These parameters are displayed:
◆
Timeout
– Sets the aging time for dynamic entries in the ARP cache.
(Range: 300 - 86400 seconds; Default: 1200 seconds or 20 minutes)
The ARP aging timeout can be set for any configured VLAN.
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