# Mac address for EM7455 **URL:** \ **Category:** MC/EM Series\ **Created:** [August 29, 2019, 5:50pm UTC](https://forum.sierrawireless.com/t/mac-address-for-em7455/17443 "2019-08-29T17:50:45Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![dchou4u](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dchou4u](https://forum.sierrawireless.com/u/dchou4u)\ **Post date:** [August 29, 2019, 5:50pm UTC](https://forum.sierrawireless.com/t/mac-address-for-em7455/17443/1 "2019-08-29T17:50:45Z")
May I ask if the MAC address on a EM7455 is stored on the module itself? So every module shipped has its unique MAC address? Is it possible to change the MAC address via AT commands? Thanks ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/jyijyi/32/4766_2.png) [@jyijyi](https://forum.sierrawireless.com/u/jyijyi)\ **Post date:** [August 30, 2019, 1:54am UTC](https://forum.sierrawireless.com/t/mac-address-for-em7455/17443/2 "2019-08-30T01:54:53Z")
I tried to connect EM7455 and MC7430 at the same time to Linux PC, they have the same mac address: owner@CNHKG-EX-001367:~/legato/packages/legato.framework.19.2.0.wp76xx-201906171244/resources/legato$ ifconfig eth2 eth2 Link encap:Ethernet HWaddr 1e:30:3f:37:72:08 BROADCAST NOARP MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) owner@CNHKG-EX-001367:~/legato/packages/legato.framework.19.2.0.wp76xx-201906171244/resources/legato$ ifconfig eth1 eth1 Link encap:Ethernet HWaddr 1e:30:3f:37:72:08 BROADCAST NOARP MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) * * * Probably this is set via GobiUSBNet.c in GobiNet driver as I saw there is some code related to MAC address. Perheps you can have a look there. ---
**Author:** ![dl5162](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/dl5162/32/2169_2.png) [@dl5162](https://forum.sierrawireless.com/u/dl5162)\ **Post date:** [August 30, 2019, 12:14pm UTC](https://forum.sierrawireless.com/t/mac-address-for-em7455/17443/3 "2019-08-30T12:14:41Z")
> [@dchou4u](#): > > May I ask if the MAC address on a EM7455 is stored on the module itself? The EM7455 has no mac address. There is no interface where it would be useful. What problem are you trying to solve? ---
**Author:** ![dchou4u](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dchou4u](https://forum.sierrawireless.com/u/dchou4u)\ **Post date:** [August 30, 2019, 1:50pm UTC](https://forum.sierrawireless.com/t/mac-address-for-em7455/17443/4 "2019-08-30T13:50:24Z")
When I do a ifconfig on the interface, I see a MAC address. Who assigns that address and how is it derived? ---
**Author:** ![jyijyi](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/jyijyi/32/4766_2.png) [@jyijyi](https://forum.sierrawireless.com/u/jyijyi)\ **Post date:** [August 30, 2019, 2:10pm UTC](https://forum.sierrawireless.com/t/mac-address-for-em7455/17443/5 "2019-08-30T14:10:12Z")
I guess gobinet driver assigned that. ---
**Author:** ![dchou4u](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dchou4u](https://forum.sierrawireless.com/u/dchou4u)\ **Post date:** [August 30, 2019, 2:31pm UTC](https://forum.sierrawireless.com/t/mac-address-for-em7455/17443/6 "2019-08-30T14:31:44Z")
Thanks for all your replies. So since multiple modems connected to the same host end up with the same MAC address, it seems to say MAC address is not needed for the packet protocol in doing switching or routing for cellular. ---
**Author:** ![dl5162](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/dl5162/32/2169_2.png) [@dl5162](https://forum.sierrawireless.com/u/dl5162)\ **Post date:** [August 30, 2019, 2:55pm UTC](https://forum.sierrawireless.com/t/mac-address-for-em7455/17443/7 "2019-08-30T14:55:30Z")
No, the mac address is not needed. The EM7455 use RMNET with raw-ip or MBIM. Neither protocol has any L2 header. The mac address is generated by the driver, and is local to the host only. It’s completely virtual. It doesn’t have any significance. The ethernet header is added and removed by the driver and never transmitted over the USB link. I still wonder what the real issue is? FYI: The qmi\_wwan driver will not use any mac address at all when operating in raw-ip mode. It creates a bare IP interface with no L2 header, matching the real packets between host and modem. ---
**Author:** ![dchou4u](https://avatars.discourse-cdn.com/v4/letter/d/e9a140/32.png) [@dchou4u](https://forum.sierrawireless.com/u/dchou4u)\ **Post date:** [August 30, 2019, 3:50pm UTC](https://forum.sierrawireless.com/t/mac-address-for-em7455/17443/8 "2019-08-30T15:50:49Z")
Hi thanks for the clear explanation. Really appreciate the time. Actually there is no issue. A coworker was asking and I didn’t have the answer. So I thought to reach out to you guys on the Forum. You guys are really helpful and thanks again.