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DHCP Client sometimes not working properly on juniper SRX210HE2

[ Edited ]
07.18.17   |  
‎07-18-2017 06:27 AM

Hello,

 

we get our static IP per DHCP from our ISP with a very shot lease time (5 Minutes), so the IP on interface ge-0/0/0.0 will be replaced very often.

 

Sometimes (one to two times a day) the routing engine fails to delete the old standard routing entry and so the routing entry are duplicated and the active entry are outdated. Then the internet is no longer reachable for the users.

2017-07-19 06_58_21-Juniper Web Device Manager.png

2017-07-18 15_12_59-Juniper Web Device Manager.png

 

Follow steps fix the routing table:

  1. Unplug ISP wire
  2. cli:   restart routing
  3. Plug IPS wire again

 

Only unplug and plug the wire doesn´t help. It delete only the oldest route and on replug the duplicate entry will be create again.

 

Software Version:   JUNOS Software Release [12.3X48-D40.5]
Bios Version:   2.8

 

How can I prevent this routing cause?

 

Thank you in advance for your help!

 

Kind regards

3 REPLIES
SRX Services Gateway

Re: DHCP Client sometimes not working properly on juniper SRX210HE2

07.18.17   |  
‎07-18-2017 08:19 PM

Hi markusB,

 

Firstly, can you check with your ISP on the 5 min IP refresh? 

 

Secondly, your IP changes close to 400 times a day. If the issue happens once or twice a day, IMO you might want to open a case with JTAC to have check this. 

 

Regards,

Anand

SRX Services Gateway

Watchdog script

07.20.17   |  
‎07-20-2017 08:01 AM

Meanwhile I have implemented a watchdog script per crontab (tcsh Script)

It´s not the best solution but minimize the impact of this behaviour.

 

echo -n `date "+%Y-%m-%d %H:%M:%S"`
echo " ### Connections test ###"
set ip_router = `/usr/sbin/cli show system services dhcp client ge-0/0/0.0 | grep router | awk -F \[ '{print $2}' | awk -F \] '{print $1}'`

if (-z $ip_router) then
   exit
endif

/sbin/ping -c 5 $ip_router

if ($? != "0") then
 echo "############################################"
 echo -n "### "
 echo -n `date "+%Y-%m-%d %H:%M:%S"`
 echo ": Restart Routing ###"
 echo "############################################"
 # /usr/sbin/cli restart routing
 echo "############################################"
endif

echo "------------------------------"
SRX Services Gateway

Re: Watchdog script

07.24.17   |  
‎07-24-2017 04:15 PM

HI markusB,

 

Recently, we are experiencing a similar problem with our SRX100, our routing table is getting filled with duplicate entries as well and our internet goes down 3-4 times a day.

 

show route 0 
0.0.0.0/0          *[Access-internal/12] 11:25:34 
                    > to XXX.XXX.XXX.97 via fe-0/0/0.0 
                    [Access-internal/12] 06:33:58 
                    > to XXX.XXX.XXX.97 via fe-0/0/0.0 
                    [Access-internal/12] 06:33:58 
                    > to XXX.XXX.XXX.97 via fe-0/0/0.0 
                    [Access-internal/12] 05:39:27 
                    > to XXX.XXX.XXX.97 via fe-0/0/0.0 
                    [Access-internal/12] 05:39:27 
                    > to XXX.XXX.XXX.97 via fe-0/0/0.0 
                    [Access-internal/12] 04:47:02 
                    > to XXX.XXX.XXX.97 via fe-0/0/0.0 
                    [Access-internal/12] 04:47:02 
                    > to XXX.XXX.XXX.97 via fe-0/0/0.0 
                    [Access-internal/12] 03:53:30 
                    > to XXX.XXX.XXX.97 via fe-0/0/0.0 
                    [Access-internal/12] 03:53:30 
                    > to XXX.XXX.XXX.97 via fe-0/0/0.0 
                    [Access-internal/12] 03:00:08 
                    > to XXX.XXX.XXX.97 via fe-0/0/0.0 

 

https://forums.juniper.net/t5/SRX-Services-Gateway/SRX-losing-internet-connection-at-random/m-p/3107...

 

We also had to unplug the modem, issue the "restart routing" command and replugging in the modem or completely restarting the SRX100 in order to regain internet access.

 

I am not familiar with watchdog, how and where do I deploy the script you provided? 

 

Thank you