topic Re: i.MX RT1064 lwIP dual Ethernet – ENET2 works standalone but not when ENET1 is enabled in i.MX RT Crossover MCUs

i.MX RT1064 lwIP dual Ethernet – ENET2 works standalone but not when ENET1 is enabled

shreya1 — Mon, 05 Jan 2026 11:40:40 GMT

I’m using i.MX RT1064 with lwIP (NXP SDK) and trying to use both ENET1 and ENET2.

ENET2 works fine when initialized alone (IP assigned, ping replies).
When both ENET1 and ENET2 are initialized, both links come up and get IPs via DHCP, but only ENET1 replies to ping.
Calling netif_set_default(&enet2_netif) does not make ENET2 respond.

Hardware, PHY, clocks, and MAC addresses are correct (ENET2 works standalone).

Question:
Does the NXP lwIP ethernetif / ENET driver assume a single netif internally?
Are RX/IRQ handlers or ethernetif_input() tied to ENET1 by default, and what is required to properly support dual ENET MACs?

Re: i.MX RT1064 lwIP dual Ethernet – ENET2 works standalone but not when ENET1 is enabled

Pablo_Ramos — Mon, 05 Jan 2026 17:12:17 GMT

Hi @shreya1,

Could you help me with the following questions?

What version of the SDK are you using?
Are you using any example as a reference? If so, which one?
Could you share how you are configuring both Ethernet interfaces?

Best Regards,
Pablo

Re: i.MX RT1064 lwIP dual Ethernet – ENET2 works standalone but not when ENET1 is enabled

shreya1 — Wed, 07 Jan 2026 03:34:27 GMT

Hi @Pablo_Ramos ,
Im using SDK version 24.12.00. Actually there are no examples related to Enet2 to refer to that im aware of. If you have any example that I might have missed, please let me know.
Im following the same steps as followed by ethernet 1 in example code exkmimixrt1064_lwip_dhcp_bm.

Re: i.MX RT1064 lwIP dual Ethernet – ENET2 works standalone but not when ENET1 is enabled

Pablo_Ramos — Wed, 07 Jan 2026 21:34:54 GMT

Hi @shreya1,

Thanks for the information.

Could you share the changes you made to configure ENET1 and ENET2 in the same example?

Are you using the EVK or a custom board?

Best Regards,
Pablo