The following article describes how to use 1G SFPs with EX9204, EX9208 and EX9214 Juniper modular Switches.

You want to use a 1G SFP in an EX9200-40XS but the interface is down.

To have this working, do the following:

• For EX9204 and EX9208, first upgrade to one of the following releases: junos:20.4R3-S4 junos:21.1R3-S3 junos:21.3R3 junos:21.4R3 junos:22.1R2 junos:22.2R1.
• For EX9214, upgrade to one of these releases: junos:21.1R2 junos:21.2R1.

In this example, there is a 1G SFP connected on FPC 1, PIC 1 and port 6:

root@EX9204-re0# run show chassis pic fpc-slot 1 pic-slot 1
Mar 17 11:09:59
FPC slot 1, PIC slot 1 information:
Type               20x10GE SFPP
State              Online 
PIC version         0.0
Uptime             29 minutes, 22 seconds
PIC port information:
             Fiber          Xcvr vendor    Wave-           Xcvr     JNPR   MSA
Port Cable type    type Xcvr vendor    part number    length          Firmware   Rev   Version
0  10GBASE SR    MM  FINISAR CORP.   AAABBBCCCDDDE-J1 850 nm          0.0      REV 01  SFF-8472 ver 10.2
6  GIGE 1000SX   MM  FINISAR CORP.   BBBCCCDDDEEEF-J3 850 nm          0.0      REV 01  SFF-8472 ver 9.3 <<<

Configure the following command:

root@EX9204-re0# set interfaces xe-1/1/6 gigether-options speed 1g 
Mar 17 10:53:30

[edit]
root@EX9204-re0# commit 
Mar 17 10:53:32
commit complete

Then the interface will be created with the correct speed of 1G but the name will remain with “xe-“. This is expected behavior.

[edit]
root@EX9204-re0# run show interfaces xe-1/1/6 terse 
Mar 17 11:04:36
Interface        Admin Link Proto  Local         Remote
xe-1/1/6        up  up
xe-1/1/6.0       up  up  inet   10.10.10.1/30  
                  multiservice

The interface speed will be configured to 1G as shown below, on the other side, a host with IP 10.10.10.2/30 exists, and we can see traffic going through the interface:

root@EX9204-re0# run show interfaces xe-1/1/6 extensive | match speed 
Mar 17 11:00:30
 Link-level type: Ethernet, MTU: 1514, LAN-PHY mode, Speed: 10Gbps, BPDU Error: None, Loop Detect PDU Error: None, Ethernet-Switching Error: None, MAC-REWRITE Error: None, Loopback: None, Source filtering: Disabled, Flow control: Enabled, Speed Configuration: 1G <<<<<

root@EX9204-re0# run ping 10.10.10.2 detail count 5      
Mar 17 11:05:03
PING 10.10.10.2 (10.10.10.2): 56 data bytes
64 bytes from 10.10.10.2 via xe-1/1/6.0: icmp_seq=0 ttl=64 time=4.397 ms
64 bytes from 10.10.10.2 via xe-1/1/6.0: icmp_seq=1 ttl=64 time=1.493 ms
64 bytes from 10.10.10.2 via xe-1/1/6.0: icmp_seq=2 ttl=64 time=1.523 ms
64 bytes from 10.10.10.2 via xe-1/1/6.0: icmp_seq=3 ttl=64 time=2.515 ms
64 bytes from 10.10.10.2 via xe-1/1/6.0: icmp_seq=4 ttl=64 time=2.009 ms

--- 10.10.10.2 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max/stddev = 1.493/2.387/4.397/1.072 ms

2023-03-17 - KB created.