SRX Services Gateway
SRX Services Gateway

SRX 320 with 4G

‎02-05-2019 07:30 PM


I have been working on a config for a 4G service on a SRX320 for a few days now, but I have come across one main things that has me stumped and a few other things that I am scratching my head over.


The first is the the IP address assigned to the 4G service ( is allocated by the SP (which is me) and is a normal everyday /32 public IP address.  The IP address gets assigned, and the service works, but when I look in the SRX's routing table, it sees the netmask as a /25 not a /32 as assigned.  So I'm not sure what's going on here...


The default route is also interesting, I configured it as nexthop dl0.0 - and the routing table it's nexthop IP address for the default route is - which isn't right to me, but, the funny thing is the service works fine - traffic comes in and traffic goes out normally.


The main problem I have is that I need to run BGP across the 4G service to the SP, but I can not get a session established, but, more worryingly, I can not telnet on port 179 to the SP equipment from th SRX - it just times out.   I'm reasonably sure that the filters are setup correctly to allow BGP to establish.  From my debug, it states that a socket to the host couldn't be opened - which I'll admit sounds just like a filtering issue, but I've been over and over it, allowing BGP and even all traffic types, but the issue remains.   A telnet in the reverse direction (from the SP back into the SRX) connects fine.


I know the SP side of things is fine as I configured and used a Cisco to achieve the desired result with out an issue. 

This feels like a bug, but...

Any help would be greatly appreciated.






SRX Services Gateway

Re: SRX 320 with 4G

‎02-07-2019 11:29 AM

Hello Lukejj,


Please note:-


If the LTE Mini-PIM gets an IP address with a mask of /32 from the service provider, the user has to configure the default gateway information using the set interfaces cl-interface cellular-options sim sim-slot gateway ip-address/mask command to make the Mini-PIM accept the assigned IP address.


[Ref:- ]


For BGP issue, it will be very helpful if you can share the configuration (partially redact IPs .) and show route output from the SRX.



SRX Services Gateway

Re: SRX 320 with 4G

‎02-10-2019 04:18 PM

Thanks for your reply, I checked out the command to add the gateway to the cl x/x/x interface, however, I don't appear to have this command available on this unit (see below).


set interfaces cl-1/0/0 cellular-options sim 1 ?
Possible completions:
<[Enter]> Execute this command
+ apply-groups Groups from which to inherit configuration data
+ apply-groups-except Don't inherit configuration data from these groups
encrypted-sim-unlock-code Encrypted PIN
> radio-access Select radio access technology
> select-profile Profile to be applied
sim-unlock-code Prompt for PIN (autoencrypted)
| Pipe through a command



Here's the BGP component of my config:


bgp {
traceoptions {
file bgp.log;
flag open detail;
group EBGP-customer-1 {
type external;
description 4g_test;
local-address x.x.29.191;
peer-as xxxxx;
local-as 65233;
neighbor y.y.112.252 
l2-learning {
global-mode switching;
rstp {
interface all;


I've had a BGP session esatablish over one of the Ge ports and it works as expected, but there is something wrong with establishing over the LTE interface. 


Here's the current route table


root@router01> show route

inet.0: 5 destinations, 5 routes (5 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both *[Access-internal/12] 00:00:05, metric2 0
> to x.x.29.192 via dl0.0
x.x.29.128/25 *[Direct/0] 00:00:05
> via dl0.0
x.x.29.191/32 *[Local/0] 00:00:05
Local via dl0.0 *[Local/0] 00:05:15
Reject *[Local/0] 00:04:55