# Change APN using +cgdcont command **URL:** \ **Category:** MC/EM Series\ **Created:** [May 15, 2019, 8:38pm UTC](https://forum.sierrawireless.com/t/change-apn-using-cgdcont-command/16413 "2019-05-15T20:38:53Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![dchou4u](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dchou4u](https://forum.sierrawireless.com/u/dchou4u)\ **Post date:** [May 15, 2019, 8:38pm UTC](https://forum.sierrawireless.com/t/change-apn-using-cgdcont-command/16413/1 "2019-05-15T20:38:53Z")
Hi I have an interesting problem… I am using a EM7450 modem. I am using the +cgdcont command to change the APN for profile 1. Since I am using a AT&T card, the APN is m2m.com.attz. I noticed a few times when I changed the APN to something like mickeymouse, the connection remains active even though this is obviously the wrong APN for the SIM card. Shouldn’t the connection go down when I change the APN to something bogus? ---
**Author:** ![Oedenburger](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/oedenburger/32/4028_2.png) [@Oedenburger](https://forum.sierrawireless.com/u/Oedenburger)\ **Post date:** [May 15, 2019, 9:38pm UTC](https://forum.sierrawireless.com/t/change-apn-using-cgdcont-command/16413/2 "2019-05-15T21:38:33Z")
Hello, at!custom - “SINGLEAPNSWITCH” Indicate device behavior when changing APN name, username, or password. : • 0 = Do nothing • 1 = Device detaches and re-attaches after changing APN information • 2 = Power-cycle the UE thanks, James ---
**Author:** ![dchou4u](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dchou4u](https://forum.sierrawireless.com/u/dchou4u)\ **Post date:** [May 15, 2019, 10:39pm UTC](https://forum.sierrawireless.com/t/change-apn-using-cgdcont-command/16413/3 "2019-05-15T22:39:33Z")
It is set to 1. Should I see the ttyUSB\* devices disappear and reappear after a while? ---
**Author:** ![dchou4u](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dchou4u](https://forum.sierrawireless.com/u/dchou4u)\ **Post date:** [May 16, 2019, 2:08am UTC](https://forum.sierrawireless.com/t/change-apn-using-cgdcont-command/16413/4 "2019-05-16T02:08:49Z")
It is set to 1 and when I changed the APN, I do not see the module disconnect from the USB bus. Did you mean it detaches and reattaches from the cell network? What was so strange to me is that the +cgdcont command with the bogus APN was sent and acknowledged by the module, but the cell connection kept going as if nothing happened. I was expecting the network to be brought down by the bogus APN. ---
**Author:** ![Oedenburger](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/oedenburger/32/4028_2.png) [@Oedenburger](https://forum.sierrawireless.com/u/Oedenburger)\ **Post date:** [May 16, 2019, 4:02pm UTC](https://forum.sierrawireless.com/t/change-apn-using-cgdcont-command/16413/5 "2019-05-16T16:02:56Z")
> [@dchou4u](#): > > Did you mean it detaches and reattaches from the cell network? Yes , it won’t disconnect from the USB bus. option 2 will reset the modem ---
**Author:** ![dchou4u](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dchou4u](https://forum.sierrawireless.com/u/dchou4u)\ **Post date:** [May 16, 2019, 4:50pm UTC](https://forum.sierrawireless.com/t/change-apn-using-cgdcont-command/16413/6 "2019-05-16T16:50:25Z")
So if the APN I entered is bogus, when it reattaches to the network again, the PDP connection should drop right? ---
**Author:** ![Oedenburger](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/oedenburger/32/4028_2.png) [@Oedenburger](https://forum.sierrawireless.com/u/Oedenburger)\ **Post date:** [May 16, 2019, 4:51pm UTC](https://forum.sierrawireless.com/t/change-apn-using-cgdcont-command/16413/7 "2019-05-16T16:51:17Z")
yes. you need to reset the modem after programming !custom ---
**Author:** ![dchou4u](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dchou4u](https://forum.sierrawireless.com/u/dchou4u)\ **Post date:** [May 16, 2019, 5:04pm UTC](https://forum.sierrawireless.com/t/change-apn-using-cgdcont-command/16413/8 "2019-05-16T17:04:37Z")
Thanks again for your reply. Actually I do not want to program !custom. I will just leave the default settings at 1. What I like to make sure is that when I program the APN with either a valid or bogus setting using +cgdcont, the expected PDP connection behavior will result. ---
**Author:** ![Oedenburger](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/oedenburger/32/4028_2.png) [@Oedenburger](https://forum.sierrawireless.com/u/Oedenburger)\ **Post date:** [May 16, 2019, 7:43pm UTC](https://forum.sierrawireless.com/t/change-apn-using-cgdcont-command/16413/9 "2019-05-16T19:43:46Z")
sorry I didn’t get the second part of your comment. > [@dchou4u](#): > > the expected PDP connection behavior will result. ---
**Author:** ![dchou4u](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dchou4u](https://forum.sierrawireless.com/u/dchou4u)\ **Post date:** [May 16, 2019, 8:01pm UTC](https://forum.sierrawireless.com/t/change-apn-using-cgdcont-command/16413/10 "2019-05-16T20:01:22Z")
Thanks for your reply. So if I use the +cgdcont command to program a bogus APN into a EM7455 module that has an active PDP connection, should it cause the PDP connection to be disrupted? ---
**Author:** ![Oedenburger](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/oedenburger/32/4028_2.png) [@Oedenburger](https://forum.sierrawireless.com/u/Oedenburger)\ **Post date:** [May 16, 2019, 11:29pm UTC](https://forum.sierrawireless.com/t/change-apn-using-cgdcont-command/16413/11 "2019-05-16T23:29:22Z")
yes it will disconnect . here is an example captured on my callbox: default is the valid APN bogus APN is not programmed in the callbox: at+cgcontrdp +CGCONTRDP: 1,5,default,192.168.2.2,8.8.8.8, OK at!custom? !CUSTOM: GPSENABLE 0x01 GPSLPM 0x01 IPV6ENABLE 0x01 UIM2ENABLE 0x01 SIMLPM 0x01 USBSERIALENABLE 0x01 SINGLEAPNSWITCH 0x01 OK at+cgdcont? +CGDCONT: 1,“IP”,“default”,“0.0.0.0”,0,0,0,0 OK at!gstatus? !GSTATUS: Current Time: 37 Temperature: 28 Reset Counter: 1 Mode: ONLINE System mode: LTE PS state: Attached LTE band: B4 LTE bw: 20 MHz LTE Rx chan: 2150 LTE Tx chan: 20150 LTE CA state: NOT ASSIGNED EMM state: Registered Normal Service RRC state: RRC Idle IMS reg state: No Srv PCC RxM RSSI: -36 RSRP (dBm): -63 PCC RxD RSSI: -57 RSRP (dBm): -83 Tx Power: – TAC: 0001 (1) RSRQ (dB): -6.0 Cell ID: 01A2D101 (27447553) SINR (dB): 28.6 OK at+cgcontrdp +CGCONTRDP: 1,5,default,192.168.2.2,8.8.8.8, OK at+cgdcont=1,“ip”,“bogus” OK at+cgcontrdp OK at!gstatus? !GSTATUS: Current Time: 79 Temperature: 28 Reset Counter: 1 Mode: ONLINE System mode: LTE PS state: Not attached LTE band: B4 LTE bw: 20 MHz LTE Rx chan: 2150 LTE Tx chan: 20150 LTE CA state: NOT ASSIGNED EMM state: Deregistered Attaching RRC state: RRC Idle IMS reg state: No Srv PCC RxM RSSI: -36 RSRP (dBm): -63 PCC RxD RSSI: -57 RSRP (dBm): -83 Tx Power: – TAC: 0001 (1) RSRQ (dB): -6.0 Cell ID: 01A2D101 (27447553) SINR (dB): 29.0 OK at+cgcontrdp OK at+creg? +CREG: 0,2 OK a/ +CREG: 0,2 OK