EX9200 auto negotiation behavior with default configuration
When EX9200 is connected to a device which supports only 100M (such as any legacy box), the link will not come up without any auto negotiation configuration
The cause of this issue is because EX9200 works in tri mode auto negotiation.
[working case (config speed explicitly)]
lab@Jazz# run show interfaces terse | match ge-2/0/1 ge-2/0/1 up up [edit] lab@Jazz# show interfaces ge-2/0/1 | display set set interfaces ge-2/0/1 speed 100m set interfaces ge-2/0/1 ether-options no-auto-negotiation NPC2(Jazz vty)# show bcm5466 registers 0 1 BCM5466 Chip Registers: MII Control Register (0x00) : 0x2100 MII Status Register (0x01) : 0x794d MII PHY ID 0 Register (0x02) : 0x0143 MII PHY ID 1 Register (0x03) : 0xbeb4 MII Auto-Neg Advertisement (0x04) : 0x0d01 ///////////////////////////////// [non-working case1 (no auto nego config)] lab@Jazz# run show interfaces terse | match ge-2/0/1 ge-2/0/1 up down [edit] lab@Jazz# show interfaces ge-2/0/1 | display set [edit] lab@Jazz# NPC2(Jazz vty)# show bcm5466 registers 0 1 BCM5466 Chip Registers: MII Control Register (0x00) : 0x1140 MII Status Register (0x01) : 0x7949 MII PHY ID 0 Register (0x02) : 0x0143 MII PHY ID 1 Register (0x03) : 0xbeb4 MII Auto-Neg Advertisement (0x04) : 0x0c01 ///////////////////////////////// [non-working case2 (no speed option)] [edit] lab@Jazz# show interfaces ge-2/0/1 | display set set interfaces ge-2/0/1 ether-options auto-negotiation [edit] lab@Jazz# run show interfaces terse | match ge-2/0/1 ge-2/0/1 up down NPC2(Jazz vty)# show bcm5466 registers 0 1 BCM5466 Chip Registers: MII Control Register (0x00) : 0x1140 MII Status Register (0x01) : 0x7949 MII PHY ID 0 Register (0x02) : 0x0143 MII PHY ID 1 Register (0x03) : 0xbeb4 MII Auto-Neg Advertisement (0x04) : 0x2c01 ///////////////////////////////// Auto-Neg Advertisement register 8bit indicate speed and duplex capability mode 0x2c01 0010 1100 0000 0001 0x0c01 0000 1100 0000 0001 0x0d01 0000 1101 0000 0001 8 bit indicate 100m FULL capability 1:100M FULL is capable 0:Not 100M FULL is capable