GRE: read() from network failed, error = Protocol not available

Hi list.

I'm getting strange denial in connection of one of my windows clients.
Here is the log:

pptpd[23533]: CTRL: Client 10.216.13.65 control connection started
pptpd[23533]: CTRL: Starting call (launching pppd, opening GRE)
pppd[23534]: Plugin /usr/lib/pptpd/pptpd-logwtmp.so loaded.
pppd[23534]: pptpd-logwtmp: $Version$
pppd[23534]: pppd 2.4.5 started by root, uid 0
pppd[23534]: using channel 593
pppd[23534]: Using interface ppp1
pppd[23534]: Connect: ppp1 <--> /dev/pts/10
pppd[23534]: sent [LCP ConfReq id=0x1 <asyncmap 0x0> <auth chap MD5>
<magic 0x857a698a>]
pptpd[23533]: GRE: Bad checksum from pppd.
pptpd[23533]: GRE: read(fd=7,buffer=80514a0,len=8260) from network
failed: status = -1 error = Protocol not available
pptpd[23533]: CTRL: GRE read or PTY write failed (gre,pty)=(7,6)
pptpd[23533]: CTRL: Reaping child PPP[23534]
pppd[23534]: Modem hangup
pppd[23534]: Connection terminated.
pppd[23534]: Exit.

Furthermore, another client (using windows too) connects successfully.
I wonder what can cause such an error. Is it configuration of my
kernel, network, router, or the client's settings?.. How that can be
fixed?


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Best regards,
max ulidtko

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