IP hosts can use several methods of deciding which default router or default gateway to use— DHCP, BOOTP, ICMP Router Discovery Protocol (IRDP), manual configuration, or even by running a routing protocol (although having hosts run a routing protocol is not common today). The most typical methods—using DHCP or manual configuration—result in the host knowing a single IP address of its default gateway. Hot Standby Router Protocol (HSRP), Virtual Router Redundancy Protocol..
Configuring AppleTalk Addresses
In this section, we examine the configuration of AppleTalk addresses on LAN and WAN interfaces. Before you assign addresses, you should develop a sensible, overall addressing scheme for your network. A few rules govern the addressing. The following are tips to help guide you: • Single network numbers should appear on only one LAN or WAN segment. • Cable-ranges should appear on only one LAN or WAN segment, and no cable-range or portion of a cable-range should b..
Carrier Detect and Interface Resets
A router has visibility into T1 framing, along with the alarm conditions, but only if the serial card has a built-in CSU/DSU. However, with an external CSU/DSU, the router has no insight into the framing or encoding on the circuit. Instead, the router can sense the voltages on the various pins on the serial cable. Table 17-4 lists and describes the purpose of the five most important signaling pins in serial cables. (Note that in this model, the term data communications equipm..
Using SNMP to Modify a Router's Running Configuration
To upload or download a current copy of your router's configuration file to a TFTP server via SNMP, you have to first configure the router for read-write SNMP access: Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#snmp-server community ORARW rw Router(config)#end To download the current configuration file, you will need to create an empty file on your TFTP server. In this case, we assume a Unix server, although TF..
Gigabit Ethernet Port Cables and Connectors
Gigabit Ethernet connections take a different approach by providing modular connectivity options. Catalyst switches with Gigabit Ethernet ports have standardized rectangular openings that can accept gigabit interface converter (GBIC) or small form factor pluggable (SFP) modules. The GBIC and SFP modules provide the media personality for the port so that various cable media can connect. In this way, the switch chassis is completely modular and requires no major change to..
