Ethernet Switching
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Ethernet Switching

EX3400 link mode half duplex

‎03-11-2020 12:05 PM

Hi,

We have EX3400 with JUNOS 18.2R3-S1.7 vesion virtual chassis configuation.

on port ge-1/0/12 i saw that port link mode is half duplex. i tried to hard core full duplex and commit the config but still its showing link mode half duplex. please suggest how can i configure full duplex. Their is no ethernet cable connected on interface.

 

--> switch1# set interfaces ge-1/0/12 link-mode full-duplex

 

switch1#show interfaces ge-1/0/12
Physical interface: ge-1/0/12, Enabled, Physical link is Down
Interface index: 814, SNMP ifIndex: 630
Link-level type: Ethernet, MTU: 1514, LAN-PHY mode, Link-mode: Half-duplex, Speed: 100mbps, Duplex: Full-Duplex, BPDU Error: None, Loop Detect PDU Error: None,
Ethernet-Switching Error: None, MAC-REWRITE Error: None, Loopback: Disabled, Source filtering: Disabled, Flow control: Disabled, Auto-negotiation: Enabled,
Remote fault: Online, Media type: Copper, IEEE 802.3az Energy Efficient Ethernet: Disabled, Auto-MDIX: Enabled

5 REPLIES 5
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Ethernet Switching

Re: EX3400 link mode half duplex

‎03-11-2020 12:41 PM

Hi Target, 

 

I hope you are doing great!

 

One question if you connect a computer on the port, does it continue working at 100mb half duplex?

 

Pablo.

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Re: EX3400 link mode half duplex

‎03-11-2020 01:39 PM

Hi Target .

 

I hope you're doing well.


It is working as per chipset design for this platform, in which the default value is 0
which maps to half-duplex when the interface is down, once you have a physical link, it should change to full-duplex


If this solves your problem, please mark this post as "Accepted Solution" so we can help others too.


Regards

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Re: EX3400 link mode half duplex

‎03-12-2020 05:40 AM

@Target and others - Just FYI but today, EX3400 does not actually support 10/100 HDX, only FDX.  HDX support is coming in a soon to be released SW version.  I know 18.2R3-S3 will/should include this support.  This SW release is due out early April, I believe.

 

Again FYI Only.

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Re: EX3400 link mode half duplex

‎03-12-2020 10:49 AM

Hello Target,

 

This is normal behavior, it will show up properly as full duplex once you connect the link.

 

By default Junos shows interfaces that appear down as half-duplex. I'll try to find a kb and post it, but this is just because when the interface is shown DOWN the duplex setting will apear as half.

 

I have handy an EX4300, look at the samples.. for an interface up the duplex shows full, while the other half duplex, i can confirm that both interfaces have the same configuration

 

Model: ex4300-24p
Junos: 18.1R3.3

 

root@EX-DESTINATION# run show interfaces extensive ge-1/0/0
Physical interface: ge-1/0/0, Enabled, Physical link is Up
Interface index: 698, SNMP ifIndex: 564, Generation: 192
Link-level type: Ethernet, MTU: 8014, LAN-PHY mode, Link-mode: Full-duplex,
Speed: Auto, BPDU Error: None, Loop Detect PDU Error: None,

 

root@EX-DESTINATION# run show interfaces extensive ge-1/0/1
Physical interface: ge-1/0/1, Enabled, Physical link is Down
Interface index: 699, SNMP ifIndex: 565, Generation: 193
Link-level type: Ethernet, MTU: 1514, LAN-PHY mode, Link-mode: Half-duplex,
Speed: Auto, BPDU Error: None, Loop Detect PDU Error: None,

 

 

root@EX-DESTINATION# run show configuration interfaces | display set
set interfaces ge-1/0/0 mtu 8014
set interfaces ge-1/0/0 unit 0 family ethernet-switching interface-mode trunk
set interfaces ge-1/0/0 unit 0 family ethernet-switching vlan members all
set interfaces ge-1/0/1 mtu 8014
set interfaces ge-1/0/1 unit 0 family ethernet-switching interface-mode trunk
set interfaces ge-1/0/1 unit 0 family ethernet-switching vlan members all

 

Best Regards,

Cheers,

Benjamin

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Re: EX3400 link mode half duplex

‎05-29-2020 07:36 AM

Hi Target,

 

Has this changed to full-duplex when you connected the host to the port?

 

Thanks,

Deimos.

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