Auto-negotiation
Auto-negotiation allows a port to
communicate with the peer port to determine the optimal speed and duplex mode for
the
connection.
Note: The default speed for fiber ports with SFP, SFPP, SFP28, QSFP, or QSFP28 is based
on
optics.
Speed optic features are not supported in the following combinations:
- The default speed on ICX 7850-48F ports 1/1/1 to 1/1/48 is 25G full-duplex.
- The default speed for ICX 7600-2X40GQ and ICX 7600-1X100GQ ports are 40G and 100G, respectively.
Port speed matrix
| auto1 | 10-half | 10-full2 | 100-half | 100-full | 1000-full | 1000-full-master3 | 1000-full-slave3 | 2500-full | 2500-full-master3 | 2500-full-slave3 | 5G-full | 5G-full-master | 5G-full-slave | 10G-full | 10G-full-master | 10G-full-slave | 25G-full4 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1G Cu (fixed ports) | Y (default) | Y5 | Y | Y5 | Y | Y | Y | Y | N | N | N | N | N | N | N | N | N | N |
| 2.5G Cu (fixed ports) | Y | N | N | N | Y67 | Y | Y | Y | Y | Y | Y | N | N | N | N | N | N | N |
| 10G Cu (fixed ports) | Y (default) | N | N | N | Y | Y | Y | Y | Y8 | Y 8 | Y8 | Y8 | Y8 | Y8 | Y | Y | Y | N |
| 1G Fiber + GBIC SFP | Y (default) | N | N | N | Y | Y | N | N | N | N | N | N | N | N | N | N | N | N |
| 10G Fiber + GBIC SFPP | N | N | N | N | N | Y | N | N | N | N | N | N | N | N | Y | N | N | N |
| 1G Fiber + 100-fx | N | N | N | N | Y 9 | N | N | N | N | N | N | N | N | N | N | N | N | N |
| 1G Fiber + 1G SFP | N | N | N | N | N | Y (default) | N | N | N | N | N | N | N | N | N | N | N | N |
| 1G Fiber + 10G SFPP (avoid) | N | N | N | N | N | N10 | N | N | N | N | N | N | N | N | N | N | N | N |
| 10G Fiber + 1G SFP | N | N | N | N | N | Y | N | N | N | N | N | N | N | N | N | N | N | N |
| 10G Fiber + SFPP | N | N | N | N | N | N | N | N | N | N | N | N | N | N | Y | N | N | N |
| 25G Fiber + 1G SFP | N11 | N | N | N | N | Y | N | N | N | N | N | N | N | N | N | N | N | N |
| 25G Fiber + GBIC, SFP | N | N | N | N | N | Y | N | N | N | N | N | N | N | N | N | N | N | N |
| 25G Fiber+ SFPP | N | N | N | N | N | N | N | N | N | N | N | N | N | N | Y | N | N | N |
| 25G Fiber + SFP28 | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | Y |
| 40G Fiber12 | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N |
| 100G Fiber13 | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N | N |
- If a port is configured with speed auto and the peer port is configured for (non autoneg) full-duplex, "duplex mismatch" occurs resulting in the local port selecting half-duplex mode. In this case, packet collisions and receive errors will occur. ↩
- In the case of speed mismatch i.e. connecting ports are set to different forced mode speeds like (100-full and 10-full) or (100-half and 10-half), the ports might not come up. This configuration is invalid. ↩
- In the case of specific master/slave selection, if the local port is selected as master, the peer port should either be set to slave (and vice-versa) or auto. ↩
- 25G ports are supported on ICX7850-48F. These ports can be configured at 25G speed only in groups of 4 ports or sets of groups of 4 ports e.g. 1/1/1-1/1/4, 1/1/1-1/1/8. ↩
- ICX 7550-24ZP and ICX 7550-48ZP 1G copper ports does not support 100M half-duplex. ↩
- ICX MultiGig ports can connect to other ICX MultiGig ports at 100 Mbps when "speed-duplex 100-full" is configured on both sides. MultiGig ports are copper ports that support 2.5G and or 5G speeds. ↩
- ICX MultiGig ports can connect to 1G copper ports on ICX switches at 100 Mbps when "speed-duplex 100-full" is configured on both sides and the 1G copper ports have EEE enabled. ↩
- On ICX 7650-48ZP, default speed is auto on
MultiGig ports and they advertize 100Mbps/1G/2.5G/5G/10G speeds by
default. Support 802.3bz and NBaseT.
ICX 7650-24ZP has 6 full Multigig ports and 18 ports of speed 100/1000/2500Mbps supporting 802.3bz and NBase-T.
ICX 7650-48ZP has 12 full Multigig ports and 36 ports of speed 100/1000/2500Mbps supporting 802.3bz and NBase-T.
↩ - The default speed of 100M applies only to ICX8200; all other devices should use 100-fx. ↩
- To be supported, use 10Gb optics at 10Gb and 1Gb optics at 1Gb. ↩
- When 25G ports on the ICX
7850-48F or 7550-4x25GF module are used with 1G optics, the remote
device must have auto-negotiation disabled. This can be accomplished
using the
gig-default neg-offcommand on the remote ICX switch. If the remote switch is from a different vendor, use the equivalent command provided by that vendor. ↩ - The default speed is based on optics and 40G-full also supported. ↩
- The default speed is based on optics and 100G-full also supported. ↩