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Connection Drops after New Modem

Discussion in 'Asuswrt-Merlin' started by Jumpstarter, Jul 11, 2019.

  1. Jumpstarter

    Jumpstarter Senior Member

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    Okay so I am running a RT-AX88U with a new modem I just purchased(Netgear CM1000), I am using Rmerlin 384.12 firmware. I keep having tons of dropped packets followed by disconnections between the router and the modem it will say DHCP server fails. I did not have this issue using a previous modem. (obviously I could factory reset and see if it fixes the issue) I am asking is there possibly a setting I need to adjust for this new modem that it doesn't play well with certain settings?
     
  2. Jumpstarter

    Jumpstarter Senior Member

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    logs of connection drops

    Code:
    Jul 11 19:56:09 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=220.194.237.43 DST=69.180.69.126 LEN=40 TOS=0x00 PREC=0x20 TTL=238 ID=29406 PROTO=TCP SPT=51789 DPT=6381 SEQ=382545741 ACK=0 WINDOW=1024 RES=0x00 SYN URGP=0
    Jul 11 19:56:11 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=52.94.233.109 DST=69.180.69.126 LEN=86 TOS=0x00 PREC=0x20 TTL=219 ID=12733 DF PROTO=TCP SPT=443 DPT=49850 SEQ=1588729140 ACK=947760829 WINDOW=2992 RES=0x00 ACK PSH URGP=0
    Jul 11 19:56:16 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=185.176.26.18 DST=69.180.69.126 LEN=40 TOS=0x00 PREC=0x20 TTL=235 ID=5346 PROTO=TCP SPT=57213 DPT=6710 SEQ=2858372010 ACK=0 WINDOW=1024 RES=0x00 SYN URGP=0
    Jul 11 19:56:31 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=178.128.254.255 DST=69.180.69.126 LEN=40 TOS=0x00 PREC=0x20 TTL=42 ID=2448 PROTO=TCP SPT=25588 DPT=23 SEQ=1169442174 ACK=0 WINDOW=27914 RES=0x00 SYN URGP=0
    Jul 11 19:57:14 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=37.143.130.124 DST=69.180.69.126 LEN=34 TOS=0x00 PREC=0x20 TTL=43 ID=30000 PROTO=ICMP TYPE=8 CODE=0 ID=30000 SEQ=0
    Jul 11 19:57:38 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=185.153.196.191 DST=69.180.69.126 LEN=40 TOS=0x00 PREC=0x20 TTL=229 ID=47215 PROTO=TCP SPT=56984 DPT=14888 SEQ=2187773753 ACK=0 WINDOW=1024 RES=0x00 SYN URGP=0
    Jul 11 19:57:38 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=185.176.26.45 DST=69.180.69.126 LEN=40 TOS=0x00 PREC=0x20 TTL=245 ID=47974 PROTO=TCP SPT=55072 DPT=1081 SEQ=3838704161 ACK=0 WINDOW=1024 RES=0x00 SYN URGP=0
    Jul 11 19:57:39 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=54.239.18.66 DST=69.180.69.126 LEN=86 TOS=0x00 PREC=0x20 TTL=222 ID=32751 DF PROTO=TCP SPT=443 DPT=34752 SEQ=1009254832 ACK=156508604 WINDOW=456 RES=0x00 ACK PSH URGP=0
    Jul 11 19:57:59 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=52.119.197.116 DST=69.180.69.126 LEN=86 TOS=0x00 PREC=0x20 TTL=231 ID=57150 DF PROTO=TCP SPT=443 DPT=58782 SEQ=3238445230 ACK=3267478890 WINDOW=456 RES=0x00 ACK PSH URGP=0
    Jul 11 19:58:02 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=92.18.121.21 DST=69.180.69.126 LEN=40 TOS=0x00 PREC=0x20 TTL=246 ID=32357 DF PROTO=TCP SPT=17441 DPT=80 SEQ=1063563726 ACK=0 WINDOW=14600 RES=0x00 SYN URGP=0
    Jul 11 19:58:03 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=52.94.242.249 DST=69.180.69.126 LEN=86 TOS=0x00 PREC=0x20 TTL=225 ID=36532 DF PROTO=TCP SPT=443 DPT=48624 SEQ=113600097 ACK=3226873488 WINDOW=1896 RES=0x00 ACK PSH URGP=0
    Jul 11 19:58:03 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=52.94.242.249 DST=69.180.69.126 LEN=86 TOS=0x00 PREC=0x20 TTL=231 ID=64083 DF PROTO=TCP SPT=443 DPT=54448 SEQ=1351034521 ACK=3513948558 WINDOW=2824 RES=0x00 ACK PSH URGP=0
    Jul 11 19:58:14 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=52.94.233.109 DST=69.180.69.126 LEN=86 TOS=0x00 PREC=0x20 TTL=219 ID=12734 DF PROTO=TCP SPT=443 DPT=49850 SEQ=1588729140 ACK=947760829 WINDOW=2992 RES=0x00 ACK PSH URGP=0
    Jul 11 19:58:43 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=198.20.99.130 DST=69.180.69.126 LEN=44 TOS=0x00 PREC=0x20 TTL=105 ID=54321 PROTO=TCP SPT=18438 DPT=9999 SEQ=839811583 ACK=0 WINDOW=32356 RES=0x00 SYN URGP=0 OPT (020405B4)
    Jul 11 19:58:58 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=183.129.160.229 DST=69.180.69.126 LEN=44 TOS=0x00 PREC=0x20 TTL=108 ID=7595 PROTO=TCP SPT=14327 DPT=44699 SEQ=3596849584 ACK=0 WINDOW=29200 RES=0x00 SYN URGP=0 OPT (020405B4)
    Jul 11 20:00:04 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=66.220.2.74 DST=69.180.69.126 LEN=84 TOS=0x00 PREC=0x20 TTL=52 ID=29907 DF PROTO=ICMP TYPE=8 CODE=0 ID=5777 SEQ=1
    Jul 11 20:00:05 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=66.220.2.74 DST=69.180.69.126 LEN=84 TOS=0x00 PREC=0x20 TTL=52 ID=29966 DF PROTO=ICMP TYPE=8 CODE=0 ID=5777 SEQ=2
    Jul 11 20:00:06 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=66.220.2.74 DST=69.180.69.126 LEN=84 TOS=0x00 PREC=0x20 TTL=52 ID=30173 DF PROTO=ICMP TYPE=8 CODE=0 ID=5777 SEQ=3
    Jul 11 20:00:21 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=119.62.193.64 DST=69.180.69.126 LEN=40 TOS=0x00 PREC=0x20 TTL=46 ID=10740 PROTO=TCP SPT=1932 DPT=60001 SEQ=1169442174 ACK=0 WINDOW=28916 RES=0x00 SYN URGP=0
    Jul 11 20:00:54 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=109.248.11.164 DST=69.180.69.126 LEN=40 TOS=0x00 PREC=0x20 TTL=242 ID=54321 PROTO=TCP SPT=57417 DPT=5925 SEQ=3062837887 ACK=0 WINDOW=65535 RES=0x00 SYN URGP=0
    Jul 11 20:01:09 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=92.118.37.74 DST=69.180.69.126 LEN=40 TOS=0x00 PREC=0x20 TTL=239 ID=64124 PROTO=TCP SPT=48893 DPT=61979 SEQ=761875737 ACK=0 WINDOW=1024 RES=0x00 SYN URGP=0
    Jul 11 20:01:14 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=93.174.93.102 DST=69.180.69.126 LEN=48 TOS=0x00 PREC=0x20 TTL=112 ID=22520 PROTO=TCP SPT=45981 DPT=465 SEQ=615201074 ACK=1792863092 WINDOW=65535 RES=0x00 SYN URGP=0 OPT (020405B401010402)
    Jul 11 20:01:56 kernel: DROP IN=eth0 OUT= MAC=34:97:f6:70:16:50:00:01:5c:7d:18:46:08:00 SRC=185.176.26.105 DST
     
  3. ApexRon

    ApexRon Senior Member

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    With most cable providers, you just can’t plug in a new cable modem without contacting them to update the MAC address in their management system. Failure to do so may cause symptoms like you described.

    Check error log of modem.
     
  4. ColinTaylor

    ColinTaylor Part of the Furniture

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    +1 for what @ApexRon said.

    Your log shows nothing unusual. That's what you'd expect to see when you turn on logging of dropped packets.
     
  5. Jumpstarter

    Jumpstarter Senior Member

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    Oh I have had them make sure everything was 100 percent on their end. New mac registered and all, trust me I wouldn't have posted here about this unless it was my last turn for advice. what is happening is the router is just straight dropping connections under normal network load, while the modem is still connected with isp. I tested this, because once it happened that the router decided to drop connection, I went and plugged unplugged everything and replugged it as far as the router goes, and connection still came up lost. I then proceded to plug the modem into a laptop just to test to see if the modem had lost connection( even though lights were all green and none in error, and no changes in modem error logs.) and I had perfect connection from modem to device ( during none of this time did I restart the modem or lose connection lights on it). Early in the day I had a technician check everything onsite, as well as I have called higher teir department support and have gotten all the troubleshooting from their end that can be possibly provided.
     
    Last edited: Jul 11, 2019
  6. Jumpstarter

    Jumpstarter Senior Member

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    upload_2019-7-11_21-13-42.png
    these are the only types of errors with the modem itself,I am seeing.
    note these populated anytime I either restart the modem, or have connection refreshed.
    note I also still wind up with a working connection at the end.
     
  7. ApexRon

    ApexRon Senior Member

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    Normal
     
    Jumpstarter likes this.
  8. ColinTaylor

    ColinTaylor Part of the Furniture

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    Can you turn off the logging of dropped packets because it's flooding the syslog with useless information. Then can you wait until the problem reoccurs and show us the syslog for that period of time. It might be helpful to have a command prompt running in the background on your PC with a continuous ping to the internet so you can see when the problem occurs, e.g. "ping -t 8.8.8.8".
     
    martinr and Jumpstarter like this.
  9. ApexRon

    ApexRon Senior Member

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    Could this be a result of being port scanned?
     
  10. Jumpstarter

    Jumpstarter Senior Member

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    I think I may have resolved the issue, I flashed down to a previous version of firmware and used reset option and cleared everything, and used a restore from that point from that previous version when conditions were excellent , and flashed back to the newer firmware, everything seems to be running better. I will see if this resolves the issue. I am no longer losing DHCP every 30 minutes. I am going to leave ping running on computer to see if connection stays active.
    thank you so much for input @ApexRon @ColinTaylor
     
  11. ApexRon

    ApexRon Senior Member

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    I'm happy you found a resolution.

    I'm a Spectrum (aka Comcast, aka TimeWarner) customer as well. I have a Netgear CM200 and an ASUS RT-86U for over a year. I wanted to share my WAN panel with you though I don't know if yours is the same. This is what works for me. I don't use ISP DNS servers out of habit from the days when I had AT&T.
    Screen Shot 2019-07-12 at 8.58.18 AM.jpg
     
  12. Jumpstarter

    Jumpstarter Senior Member

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    this is the issue that happens with my router when the symptoms start log say
    Jul 12 14:01:23 WAN_Connection: ISP's DHCP did not function properly.
    Jul 12 14:01:24 DualWAN: skip single wan wan_led_control - WANRED off

    then it starts the reconnection process
     
  13. Jumpstarter

    Jumpstarter Senior Member

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    my wan connection page looks similar but I have aggressive selected at the bottom, but this should affect the router if it is randomly dropping connection, but only when it is trying to establish connection.
     
  14. ApexRon

    ApexRon Senior Member

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    Consider changing to 'Normal' at the very least to just give it a try. I took a screen capture of the help for that function.
    Screen Shot 2019-07-12 at 2.17.29 PM.jpg
     
  15. Jumpstarter

    Jumpstarter Senior Member

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    well the issue appears to be the modem itself restarting on its own. I looked at the time on the modem and the logs look exactly the same as if Comcast sent a signal to restart the modem, it happened around the same time I got the logs on my syslog on the router saying
    Jul 12 14:01:23 WAN_Connection: ISP's DHCP did not function properly.
    Jul 12 14:01:24 DualWAN: skip single wan wan_led_control - WANRED off
     
  16. Jumpstarter

    Jumpstarter Senior Member

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    I don't see how this setting would cause the modem to lose connection with isp.
     
  17. ApexRon

    ApexRon Senior Member

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    Is it the chicken or the egg?????

    Did Comcast reset the modem because of the aggressive behavior of the router? Comcast can do that. Or did the modem reset out of the blue causing the error?

    Humor me.... Change the setting to normal.
     
  18. Jumpstarter

    Jumpstarter Senior Member

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    I will try it, last time I attempted this setting the router didn't have internet connection on reboots.
     
  19. Jumpstarter

    Jumpstarter Senior Member

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    in this case wouldn't options
    Code:
    Extend the TTL value
    Spoof LAN TTL value
    help as well?
     
  20. Jumpstarter

    Jumpstarter Senior Member

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    You would think if Comcast did do something like this they would atleast keep a record of it, when someone calls them for technical support, they could let them know the problem so the customer can address it.