[ale] Wow... Jacktrip or Jamulus KILLS Cisco Router??

[neal at mnopltd.com]

That's a great idea, at least for diagnosis, since I can cause this 
failure any evening I want.

I can at least force an nslookup on a PC to use those and see if it 
works or not.

One really really weird thing: I noticed three warnings in the Cisco 
logs maybe-about the time of failure complaining that IPV6 was not 
configured.  Which it is not.  Ever.   Did the Cisco get a wild hare and 
decide to NAT all the DNS traffic through IPV6?

Thanks and regards,

Neal

> Have you tried using another public DNS service instead of Comcast.
> I’ve found Comcast DNS to be extremely unreliable and I use a
> combination of OpenDNS (208.67.222.222 and 208.67.220.220) and
> Cloudfare (1.1.1.1 and 1.0.0.1).  I’ve heard others use Google or
> Comodo.   All of these are publicly available.
> 
> Ray

On 2021-02-13 21:59, Raylynn Knight wrote:
>> On Feb 13, 2021, at 2:37 PM, Neal Rhodes via Ale <ale at ale.org> wrote:
>> 
>> I will apologize in advance for not taking some of the advice given on 
>> our church WAN/LAN regarding making 10.1.10.X see 192.168.x.x.
>> 
>> The stock small business Comcast router setup is what they call 
>> "virtual bridge mode", meaning no firewall, and being a hybrid 
>> voice/data configuration any significant changes risks bringing the 
>> whole house down.  With no support from them to get it back up.
>> 
>> I have the access we need working, retaining our Ubuntu audio server 
>> on the comcast side, and letting our cisco router act as firewall, and 
>> I haven't brought down questions about murky security issues. yet.
>> 
>> BUT this has to be one for the record books... Configuration:
>> 
>> Comcast Router <==> Cisco RV180vpn Router <==> 192.168.x.x: Virtual 
>> Studio/Jambox
>> +Ubuntu Jack/Jamulus
>> 
>> Comcast router, with Ubuntu server running Jacktrip and Jamulus.  
>> Normal Comcast 10.X.X.X network.
>> 
>> Cisco Router providing 192.168.x.x LAN behind it.
>> 
>> Now comes the weird part... outside VS boxes can hit the Jacktrip or 
>> Jamulus all day, for hours, no problem. JackTrip uses TCP port 4464, 
>> and UCP 51002-62000.   Jamulus just uses UDP 22124.   Once fired up, 
>> these are wailing away sending either uncompressed (jacktrip) or 
>> compressed (Jamulus) audio.
>> 
>> BUT, fire up the VS box on the LAN, connecting to the Jacktrip or 
>> Jamulus server sitting on the Comcast box, and within 2 hours NOTHING 
>> on the LAN will be able to get DNS service.   Not immediately, but 
>> within 2 hours.   The Cisco box doesn't fake DNS; it tells clients to 
>> hit 75.75.75.75, or 75.75.76.76, the standard Comcast ports.   The DNS 
>> failure is visible both in the Cisco router's Diagnostic tools, AND 
>> from a browser, AND from nslookup on a PC.  The Ubuntu box outside the 
>> LAN continues to have normal DNS responses.
>> 
>> We can still PING external hosts we have an IP address for.    I was 
>> able to ping my house router.
>> 
>> This has happened three different days, and in each instance, a simple 
>> reboot of the Cisco router has resolved it for days.   Until Virtual 
>> Studio or Jambox is started again.   Today, being Saturday, there was 
>> NO activity besides me.
>> 
>> And on Sundays, we have been streaming video without incident.
>> 
>> The Cisco RV180VPN is in fact not running latest firmware.  I have 
>> another coming (I hope) on Ebay and will flash that with latest and 
>> try it.  Beyond that,  what?   I guess we could buy a brand new router 
>> with current support...
>> 
>> From a local PC: nslookup
>> DNS request timed out.
>>    timeout was 2 seconds.
>> Default Server:  UnKnown
>> Address:  75.75.75.75
>> 
>>> google.com
>> Server:  UnKnown
>> Address:  75.75.75.75
>> 
>> DNS request timed out.
>>    timeout was 2 seconds.
>> DNS request timed out.
>>    timeout was 2 seconds.
>> DNS request timed out.
>>    timeout was 2 seconds.
>> DNS request timed out.
>>    timeout was 2 seconds.
>> *** Request to UnKnown timed-out
>> 
>> I also tried nslookup - 75.75.76.76 with identical results.
>> 
>> My wife suggested I should run a traceroute to the DNS server when 
>> it's working, and then again when it fails.  I should listen to her 
>> more often.
>>