Can't download packages on fresh install

Hi Openwrt community,

I'm a newbie who got into this world last night. I flashed my old Linksys WHW01 with latest Openwrt, setup a root pass, and a wifi network.

I'm trying to install packages on my router via opkg, but I'm getting following error:

opkg_download: Check your network settings and connectivity.

Here's my setup. Modem -> ISP router (DHCP server) -> switch -> Linksys router with Openwrt (DHCP server)

My wifi on Openwrt router is working. I'm able access internet, but when I'm trying to install packages via SSH on a LAN connection, I'm getting this error.

I think it is a DNS/Network problem because when I ping, I'm getting this error:

ping: bad address ''

When I ping

ping: sendto: Network unreachable

How are you connecting the linksys OpenWrt device to your network? Is it via the lan port on the linksys or the wan port?

Have you synced the time and set the timezone??
In LuCI:

I have not. Let me try

There's no wan port on the Linksys router. I can use either one as per the documents. I don't think that is an issue, otherwise wifi on linksys won't be working.