Linksys WRT3200ACM enabling multiple radios?

Installing and Using OpenWrt
1

Hi,

I'm running OpenWRT 18.06.2 on a WRT3200ACM, and it shows 3 wireless radios.

I was hoping I could run both 5ghz and 2.4ghz, but if I enable any 2 of the radios, the router becomes unusable quickly--if I have a ping running and I'm connected (wired) to the lan, I see a distinct pattern of the router's address staying reachable and responding to ping for ~30s, then down for ~60s, then up for about 30s, then down again for longer, and then sporadic episodes of being up for 3-10s at a time.

I'm not sure what's happening and I'm not sure how best to troubleshoot it, because of the connectivity troubles and being unable to stay on. Usually after rebooting, I can get an address and send in a uci set wireless.radio1.disabled='1', and then the next reboot ends up ok.

What I've seen so far is that top shows nothing interesting if I watch it during the first 30s of connectivity, and dmesg shows no new messages relative to before enabling the 2nd radio during the 2nd bout of connectivity, but I haven't dug very far on trying other ideas.

Here's my uci show wireless after clicking "Enable" on the 2nd radio on luci, during my first 30s or so of connectivity:

wireless.radio0=wifi-device
wireless.radio0.type='mac80211'
wireless.radio0.hwmode='11a'
wireless.radio0.path='soc/soc:pcie/pci0000:00/0000:00:01.0/0000:01:00.0'
wireless.radio0.htmode='VHT80'
wireless.radio0.country='US'
wireless.radio0.legacy_rates='1'
wireless.radio0.channel='40'
wireless.default_radio0=wifi-iface
wireless.default_radio0.device='radio0'
wireless.default_radio0.network='lan'
wireless.default_radio0.mode='ap'
wireless.default_radio0.ssid='holland'
wireless.default_radio0.encryption='psk-mixed'
wireless.default_radio0.key='xxx'
wireless.radio1=wifi-device
wireless.radio1.type='mac80211'
wireless.radio1.hwmode='11g'
wireless.radio1.path='soc/soc:pcie/pci0000:00/0000:00:02.0/0000:02:00.0'
wireless.radio1.htmode='HT20'
wireless.radio1.country='US'
wireless.radio1.legacy_rates='1'
wireless.radio1.channel='2'
wireless.default_radio1=wifi-iface
wireless.default_radio1.device='radio1'
wireless.default_radio1.network='lan'
wireless.default_radio1.mode='ap'
wireless.default_radio1.encryption='psk-mixed'
wireless.default_radio1.key='xxx'
wireless.default_radio1.ssid='holland_24ghz'
wireless.radio2=wifi-device
wireless.radio2.type='mac80211'
wireless.radio2.hwmode='11a'
wireless.radio2.path='platform/soc/soc:internal-regs/f10d8000.sdhci/mmc_host/mmc0/mmc0:0001/mmc0:0001:1'
wireless.radio2.htmode='VHT80'
wireless.radio2.channel='auto'
wireless.radio2.country='US'
wireless.radio2.legacy_rates='1'
wireless.default_radio2=wifi-iface
wireless.default_radio2.device='radio2'
wireless.default_radio2.network='lan'
wireless.default_radio2.mode='ap'
wireless.default_radio2.ssid='holland'
wireless.default_radio2.encryption='psk-mixed'
wireless.default_radio2.key='xxx'
wireless.default_radio2.disabled='1'

After that, by waiting for the right moment after a power cycle and sending in some commands to reset, I was able to recover without having to re-flash this time:

uci show wireless ; dmesg ; uci set wireless.default_radio1.disabled='1' ; uci set wireless.radio1.disabled='1' ; uci commit ; uci show wireless ; reboot

It seems to get progressively worse and to exhibit the same behavior (with perhaps a smaller window of basic lan connectivity) even after a power cycle.

Has anybody else seen anything like this? Any top candidates of things I should try looking at while I've got ~5s of command-line connectivity? Or better yet, anything I should look at while the 2nd radio is not enabled that might give a good hint what's going wrong?

Thanks.

2

Start by disabling the radio2 ( the one with the hardware path sdhci mmc etc.). It has not been originally meant for actual use, and was designed for just radar detection and/or WiFi ap scanning.

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3

Is your PC or anything else set to connect to either of the radios? It may be creating a network loop between the wifi and Ethernet. Enable STP on the LAN interface.

4

STP was a great idea that would have explained everything, but alas it didn't work.

radio2 was already disabled, thanks. I saw that mentioned elsewhere, so I was trying to enable just 0 and 1 (0 is 5ghz, 1 is 2.4ghz).

I added a "uptime" to the front of my recover command string, and confirmed that whatever's happening, there's an unexpected reboot shortly before the 2nd pass at getting connectivity back.

Any other ideas to try? Thanks :slight_smile:

5

This is something that is well established to work properly on that model with the 18.06.2 release. I suggest resetting to default configuration and make as few changes as possible other than set up the APs.

If that doesn't work, flash back to stock firmware to confirm there isn't a hardware problem.

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6

OK, this seems to be a problem with WPA-PSK + WPA2-PSK mixed mode, I think.

When I pick that on both, this was an easily reproducible issue, but if I just pick WPA2-PSK on both, I can turn on both radios and everything seems reasonably happy.

Thanks.

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