@Paul_wb 

 

Well, are you using the SAME network settings? That is same SSID and Gateway IP Address?

 

I'll also assume that Ping to an Internet address on both LAN devices are 'normal'? I suspect they may not be?

 

Some devices can 'hold' data from old connections when you put a different device in the same place.

 

If you did, first thing I'd do is put back the old router and verify it still works fine. If it does, then put the A20 back but change the SSID name. Then reconnect, that should reset the network on the 2 devices to be new. Test again.

 

Can't always go by PING either as the times do vary by device. I'm on an A20 V1, and here are some LAN pings for me, wife's PC, my LAN connected phone, and our printer:

 

=================

C:\>ping 192.168.0.124

Pinging 192.168.0.124 with 32 bytes of data:
Reply from 192.168.0.124: bytes=32 time=4ms TTL=128
Reply from 192.168.0.124: bytes=32 time=4ms TTL=128
Reply from 192.168.0.124: bytes=32 time=4ms TTL=128
Reply from 192.168.0.124: bytes=32 time=4ms TTL=128

Ping statistics for 192.168.0.124:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 4ms, Maximum = 4ms, Average = 4ms

 

C:\>ping 192.168.0.141

Pinging 192.168.0.141 with 32 bytes of data:
Reply from 192.168.0.141: bytes=32 time=182ms TTL=64
Reply from 192.168.0.141: bytes=32 time=188ms TTL=64
Reply from 192.168.0.141: bytes=32 time=301ms TTL=64
Reply from 192.168.0.141: bytes=32 time=326ms TTL=64

Ping statistics for 192.168.0.141:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 182ms, Maximum = 326ms, Average = 249ms

 

C:\>ping 192.168.0.182

Pinging 192.168.0.182 with 32 bytes of data:
Reply from 192.168.0.182: bytes=32 time=18ms TTL=64
Reply from 192.168.0.182: bytes=32 time=32ms TTL=64
Reply from 192.168.0.182: bytes=32 time=39ms TTL=64
Reply from 192.168.0.182: bytes=32 time=58ms TTL=64

Ping statistics for 192.168.0.182:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 18ms, Maximum = 58ms, Average = 36ms

C:\>

 

The first one is my Win10 PC to her Win10 PC and it clearly is the fastest (all device are wireless).

 

More confusing is 3 consecutive runs to my phone:

 

C:\>ping 192.168.0.141

Pinging 192.168.0.141 with 32 bytes of data:
Reply from 192.168.0.141: bytes=32 time=5ms TTL=64
Reply from 192.168.0.141: bytes=32 time=24ms TTL=64
Reply from 192.168.0.141: bytes=32 time=4ms TTL=64
Reply from 192.168.0.141: bytes=32 time=4ms TTL=64

Ping statistics for 192.168.0.141:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 4ms, Maximum = 24ms, Average = 9ms

C:\>ping 192.168.0.141

Pinging 192.168.0.141 with 32 bytes of data:
Reply from 192.168.0.141: bytes=32 time=200ms TTL=64
Reply from 192.168.0.141: bytes=32 time=114ms TTL=64
Reply from 192.168.0.141: bytes=32 time=119ms TTL=64
Reply from 192.168.0.141: bytes=32 time=117ms TTL=64

Ping statistics for 192.168.0.141:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 114ms, Maximum = 200ms, Average = 137ms

C:\>ping 192.168.0.141

Pinging 192.168.0.141 with 32 bytes of data:
Reply from 192.168.0.141: bytes=32 time=172ms TTL=64
Reply from 192.168.0.141: bytes=32 time=202ms TTL=64
Reply from 192.168.0.141: bytes=32 time=38ms TTL=64
Reply from 192.168.0.141: bytes=32 time=111ms TTL=64

Ping statistics for 192.168.0.141:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 38ms, Maximum = 202ms, Average = 130ms

 

Three somewhat different results? However, PC to PC doesn't take a lot of MS's.

 

@IrvSp Thanks for following up. I'll try to work through your comments:

 

1. Yes I'm using the same SSID and same Gateway IP address on both devices, however as mentioned below the SSID is different than it was with the old router.

2. Pings to an internet address (e.g., google.com) are all consistent and under 15ms from both devices.

3. Unfortunately I sold the old router so I don't have any way to go back and test. When i set up the A20 I used a new SSID name so I don't see any way the devices would confuse the A20 with the old router.

4. I agree that ping is a sub-optimal diagnostic, I'd love to hear ideas for other ways I can poke at this problem to try to understand what might be going wrong. If you want evidence of how little I know how to diagnose this problem, I tried a traceroute and it happily shows:

traceroute to 192.168.0.111 (192.168.0.111), 64 hops max, 72 byte packets
 1  192.168.0.111 (192.168.0.111)  52.980 ms  3.319 ms  2.718 ms

 

Cool, thanks traceroute, you've been a great help.

 

The best diagnostic I've found is how horribly unstable ssh is. Especially when i use ssh with port forwarding (if you are intersted, i run jupyternotebooks on the desktop and then access them through a browser on the laptop... before the A20 it worked perfectly, wish I had noticed the problem before selling the old router) it may connect for 10 minutes and then just completley give up or it may just fail horribly from the moment I connect.

 

I'm completely clueless here. The only thing I learned that might be a clue to the difference was also from this forum: https://community.tp-link.com/us/home/forum/topic/203974 I didn't know that the A7 had NAT loopback and the A20 got rid of it?

@Paul_wb 

 

One other thing to look at, channels being used. Could have some interference or congestion. Try using different channels.

 

Turn off MU-MIMO if you turned it on, and check that QoS is set to standard. These could cause some problems.

 

On my V1 I had to set WPA2, and AUTO picked plain WPA, but I'd not think that would matter. I discovered this under Windows what I looked at the properties for the connection.

I suspect you are not running Windows? I have used LAN SPEED TEST (https://totusoft.com/lanspeed) and I ran it from both PC's. Not sure it will show you much, but they should have about the same data using both PC's as servers. Only for Windows and Mac though. Wondering if the Anti-Virus is getting in the way? Could try disabling those 3 items and test?

Interesting. I get perfect speeds using the LAN_speedtest between the computers. I thought it was strange that I'm really only seeing this problem with ssh and, wow, of course there was something I was missing: Apple released an OS update right around the time I upgraded routers and people are reporting that it broke SSH.

 

Just google "catalina ssh" for details.

 

I bounced around a few suggestions and ended up doing something similar to what is recommended here: https://jeromejaglale.com/doc/mac/fix_ssh_connection_delays

 

I suspect that setting "UseDNS no" in /etc/ssh/sshd_config may be what made the difference.

 

I have no idea now whether the problem is the catalina ssh bug or if there is something broken with DNS in how i have the A20 setup right now... For the moment it seems that my ssh connections are more reliable so maybe that fixed things? I guess if anyone ever has a similar problem and there are no more posts on this thread then assume that, yes, that change fixed it.

 

BTW my setup for this is a macbook pro on 10.15.6 and a mac mini on 10.15.6 Thanks again IrvSp, I'm not sure exactly which part of what you said made me suspicious, but it was definitely inspired by your brainstorming!