get "Destination Host Unreachable" with no resaon !!

hi guys
i have a very confusing problem that caught and get me crazy. please and please anyone help me

i have a Asterisk base PBX VM (Issabel 4) and a SIP Trunk Line that connect to a modem.
my modem IP is "" and i connect that directly to an ESXi server and attached that to a VM(my PBX)
my PBX IP is ""
when i setup entire system i had no problem and system goes very well but after 1 or 2 day my SIP TRUNK calls suddenly lost and every body's call has been terminate!!
i have other connection via a sangoma Vega50 External Gateway(for my analog telephone lines) and it's work very well ... i mean i'm pretty sure my PBX does not have a problem but when i ping my SIP TRUNK's modem in a period time like 24 hours , i see errors like this :

64 bytes from icmp_seq=11037 ttl=255 time=4.43 ms
64 bytes from icmp_seq=11038 ttl=255 time=4.65 ms
64 bytes from icmp_seq=11039 ttl=255 time=4.36 ms
64 bytes from icmp_seq=11040 ttl=255 time=4.38 ms
64 bytes from icmp_seq=11041 ttl=255 time=5.92 ms
64 bytes from icmp_seq=11042 ttl=255 time=4.54 ms
64 bytes from icmp_seq=11043 ttl=255 time=4.42 ms
64 bytes from icmp_seq=11044 ttl=255 time=4.41 ms
From icmp_seq=11065 Destination Host Unreachable
From icmp_seq=11066 Destination Host Unreachable
From icmp_seq=11067 Destination Host Unreachable
From icmp_seq=11068 Destination Host Unreachable
From icmp_seq=11069 Destination Host Unreachable
From icmp_seq=11070 Destination Host Unreachable
From icmp_seq=11071 Destination Host Unreachable
From icmp_seq=11072 Destination Host Unreachable
From icmp_seq=11073 Destination Host Unreachable
From icmp_seq=11074 Destination Host Unreachable
From icmp_seq=11075 Destination Host Unreachable

the connection between PBX and SIP modem has been lost for couple of seconds but that's enough for terminating calls and bad call experience for users.

i don't know why but let's you know what i do for this problem until now:

1) i change my cable connection (twice)
2) i change my Sip TRUNK modem
3) i change my physical LAN port
4) i change my Entire Server ( install new issabel on another ESXi server)
note: i test ESXi 6.5 and 6.7 both have same problem !

i don't know what is my problem
i guess it's must be my ESXi settings but i don't face this problem on my 10 years of my work

please and please some one help me

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Reply to: get "Destination Host Unreachable" with no resaon !!
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Small world.

I take it this happens infrequently. You wrote it happens over 24 hours and not instantly. We had such happen and traced it to a network switch. It was expensive to figure it out with weeks of testing which was upsetting since it was a 10 dollar network switch that would every 24 hours just fail to get packets through for a short time then work again.

I will share this was for a packaged system that the company I worked for was selling and the fix was another make switch. Management wanted a fix that didn't require paying for a 12 dollar switched hub. This investigation took weeks, then weeks of heated meetings since management wanted a fix. Engineering had done the work, but you can imagine the heat some took and received over one bum part.

What I find when this sort of issue comes up, some owners push back about changing out bum hardware. It could be your config but you do this all the time so to reach out like this, you have to be open to what others encounter.

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it was not my answer but thanks for your information

thanks but still i don't get my answer !!

somebody please help to understand this problem please

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Need more.

I read your post and it sounds as if this is a problem that comes and goes. My example was to share where we had such and what we tracked it down to, along with the troubles we had with management wanting a fix that didn't involve replacing the failing gear.

I can't tell you if your IP plan is bogus. That's for you and the supplier to map out. It is odd to see the /30 but hey, you're the one that did that!

I do understand the problem as well as how companies can be loathe to fix it.

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