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Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
OL-10101-02
Chapter 12 Configuring LRE
Configuring LRE Ports
Guidelines for Configuring Cisco 575 LRE CPEs and 576 LRE 997 CPEs
You can configure the CPE Ethernet port to operate at 10 or 100 Mbps and at half- or full-duplex mode,
depending on the capability of the remote Ethernet device. Autonegotiation for port speed and duplex
mode is supported.
The default speed for the CPE Ethernet port is auto. The default duplex mode is half duplex with back
pressure.
When the default speed is set to 10 or 100 Mbps with half duplex, the values set are the same. Table 12-5
shows the speed and duplex settings on the CPE Ethernet port and the switch Ethernet port.
Note The LRE link speed and duplex values are profile independent. All LRE links have a default speed of
100 Mbps with half duplex except for the profile LRE-10 (on the Catalyst 2950ST-8 LRE and 2950ST-24
LRE switches), which is set to 10 Mbps with full duplex.
The speeds on the LRE links and CPE Ethernet links do not need to match. However, to prevent the
possible loss of data when the LRE link is slower than the CPE Ethernet link, make sure that the CPE
Ethernet port is set to half-duplex mode. Use duplex autonegotiation only if the remote device supports
802.3x full-duplex flow control. The PC user should notice no significant difference in performance
between 100-Mbps half duplex and 100-Mbps full duplex. Use the cpe duplex and cpe speed interface
configuration commands, respectively, to configure the duplex and speed settings on the Cisco 575 LRE
CPE or the 576 LRE 997 CPE Ethernet port.
You cannot disable CPE toggle on a link from a Cisco 575 LRE or Cisco 576 LRE CPE to a remote
device (such as a PC).
Guidelines for Configuring Cisco 585 LRE CPEs
You can configure the Cisco 585 LRE CPE Ethernet port speed and duplex mode from the CLI,
depending on the capability of the remote Ethernet device. Autonegotiation for CPE port speed and
duplex mode is supported. Use the cpe duplex and cpe speed interface configuration commands,
respectively, to configure the duplex and speed settings on a Cisco 585 LRE CPE Ethernet port.
The default speed for the CPE Ethernet ports is auto. The default duplex mode is half duplex at 100 Mbps
with back pressure.
You can enable or disable the CPE Ethernet ports on a per-port basis.
You can disable CPE toggle on a Cisco 585 LRE CPE.
Tab l e 12-5 Speed and Duplex Settings
CPE LRE Switch
Speed Duplex Speed Duplex
10 Full 10 Half
10 Half 10 Half
100 Full 100 Half
100 Half 100 Half