Ethernet Media Configuration Overview
You can configure the CTP Ethernet media to autonegotiate and set the speed to either 100 or 10 Mbps. By default, autonegotiation is enabled and the speed is to 1000 Mbps. If you choose to disable autonegotiation, the system prompts you to configure the desired speed.
The Ethernet configurations on CTP must match the configuration of the connected router or switch. Mismatched configurations, such as setting the CTP system to autonegotiate and the router to full duplex, will result in a misconfiguration and dropped packets. You must disable Cisco Discovery Protocol on the Fast Ethernet port connected to the CTP system.
Table 1 lists the valid Ethernet media configuration settings that CTP Series supports.
Speed |
Autoneg Status |
Mode (Duplex) |
MTU (up to 1500) |
|---|---|---|---|
1000 |
ON |
Full |
any |
100 |
OFF |
Full |
any |
10 |
OFF |
Full |
any |
The CTP system supports only full duplex mode.
Support for Full-Duplex Mode Only on NIC Ports Connected to CTP Devices
If the autonegotiation setting of the CTP Ethernet media and the far-end switch or router do not match, it is possible for the CTP Ethernet ports to be in a half-duplex state, although the duplex setting is not configurable and always assumed to be full-duplex on the CTP device. Starting with CTPOS and CTPView Release 7.2, only full-duplex mode is supported on the network interface card (NIC) ports of the far-end switch or router connected to the CTP devices and if you do not configure full-duplex on NIC ports during the autonegotiation process, then the interfaces are considered to be down and a log message is recorded in both the /var/log/messages directory and the syslog file stating that the interface is down due to a non-full duplex condition. You are prompted to verify the cable connection, speed, and duplex settings because the NIC link might be down.
The default speed for autonegotiation is 100 Mbps. To configure Ethernet interfaces on a CTP device using the CTP Menu, from the Main Menu, select 5) Node Operations. Display the current Ethernet configuration by selecting 12) Config ethernet media. You can configure autonegotiation to be enabled, which sets the speed as 1000 Mbps. Mismatched configurations, such as setting the CTP system to autonegotiate and the router to full duplex, may result in a misconfiguration and dropped packets. You must disable Cisco Discovery Protocol on the Fast Ethernet port connected to the CTP system.