# Network problem with eth0:1(192.168.2.99)

**URL:** <https://discuss.pynq.io/t/network-problem-with-eth0-1-192-168-2-99/5548>\
**Category:** Support\
**Created:** [May 4, 2023, 9:44am UTC](https://discuss.pynq.io/t/network-problem-with-eth0-1-192-168-2-99/5548 "2023-05-04T09:44:38Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Zeuskj](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/zeuskj/32/4622_2.png) [@Zeuskj](https://discuss.pynq.io/u/Zeuskj)\
**Post date:** [May 4, 2023, 9:44am UTC](https://discuss.pynq.io/t/network-problem-with-eth0-1-192-168-2-99/5548/1 "2023-05-04T09:44:38Z")

</div>

When I am using Pynq z2 these days, I suddenly encounter the problem as @kumamon suffered many years ago. The link is here: [Unable to access 192.168.2.99](https://discuss.pynq.io/t/unable-to-access-192-168-2-99/719)  
I try to search the solution on the Internet but there is no certain way. Finally I find a way maybe can solve the problem to some extent.  
Here is the problem I meet:  
I connect the board with my pc. Yesterday, just after I reboot the board with the switch on the board, the eth0:1 which is used to be set as 192.168.2.99 disappeared using **ifconfig** command and I cannot access the board through this ip. Instead, a sit:0 device appeared when I use **ifconfig -a** command. I try to use **sudo ifconfig eth0:1 192.168.2.99 up** , the eth0:1 will appear for a few second and shutdown automatically as before. I think maybe it is caused by my pc, so I changed another pc. However, the problem still exists. I try to connect the board to the WIFI router directly and it works well. But the RPC module I am using do not allow this kind of connection so I decided to find a way.  
After a day of trying, I finally find a way to solve the problem. Here is what I do:  
The default eth0 file in /etc/network/interfaces.d is

> auto eth0  
> iface eth0 inet dhcp
> 
> auto eth0:1  
> iface eth0 inet static  
> address 192.168.2.99  
> netmask 255.255.255.0

I switch the eth0 and eth0:1:

> auto eth0:1  
> iface eth0 inet dhcp
> 
> auto eth0  
> iface eth0 inet static  
> address 192.168.2.99  
> netmask 255.255.255.0

After rebooting, I can connect the board with 192.168.2.99, but there is still no eth0:1 using **ifconfig** command. Anyway, I can continue my project.  
The problem is really weird because the eth0:1 seems to shutdown every time I connect the board to the pc. But when I connect it to the router, it seems to work because it appears using **ifconfig** command.