random ports blocked on client's firewall when mounting nfs share - why?











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Could you help me, how can I prevent this?
Every time, when I mount an nfs share, I see 6-7 blocked packets in the client's firewall log. These packets come from and to random tcp ports, but they are the same at every mount.
For example, after this command:



mount -t nfs server:/logs /logs


I see in the firewall log/journalctl output:



nov 16 15:46:22 machine kernel: [UFW BLOCK] IN=wlp1s0 OUT= MAC=<mac addresses> SRC=<NFS server's IP> DST=<client's IP> LEN=60 TOS=0x00 PREC=0x00 TTL=63 ID=34612 DF PROTO=TCP SPT=695 DPT=37123 WINDOW=29200 RES=0x00 SYN URGP=0i


repeated 6 times.
After umounting, then mounting it again, I see:



nov 16 16:16:18 machine kernel: [UFW BLOCK] IN=wlp1s0 OUT= MAC=<mac addresses> SRC=<NFS server's IP> DST=<client's IP> LEN=60 TOS=0x00 PREC=0x00 TTL=63 ID=54001 DF PROTO=TCP SPT=915 DPT=37123 WINDOW=29200 RES=0x00 SYN URGP=0


repeated 6 times again.
Etc.



First of all: why? What the NFS server wants from my client? And how can I fix it (to use the same port every time)?






linux networking firewall mount nfs







share|improve this question


























    up vote
    0
    down vote

    favorite












    Could you help me, how can I prevent this?
    Every time, when I mount an nfs share, I see 6-7 blocked packets in the client's firewall log. These packets come from and to random tcp ports, but they are the same at every mount.
    For example, after this command:



    mount -t nfs server:/logs /logs


    I see in the firewall log/journalctl output:



    nov 16 15:46:22 machine kernel: [UFW BLOCK] IN=wlp1s0 OUT= MAC=<mac addresses> SRC=<NFS server's IP> DST=<client's IP> LEN=60 TOS=0x00 PREC=0x00 TTL=63 ID=34612 DF PROTO=TCP SPT=695 DPT=37123 WINDOW=29200 RES=0x00 SYN URGP=0i


    repeated 6 times.
    After umounting, then mounting it again, I see:



    nov 16 16:16:18 machine kernel: [UFW BLOCK] IN=wlp1s0 OUT= MAC=<mac addresses> SRC=<NFS server's IP> DST=<client's IP> LEN=60 TOS=0x00 PREC=0x00 TTL=63 ID=54001 DF PROTO=TCP SPT=915 DPT=37123 WINDOW=29200 RES=0x00 SYN URGP=0


    repeated 6 times again.
    Etc.



    First of all: why? What the NFS server wants from my client? And how can I fix it (to use the same port every time)?






    linux networking firewall mount nfs







    share|improve this question
























      up vote
      0
      down vote

      favorite









      up vote
      0
      down vote

      favorite











      Could you help me, how can I prevent this?
      Every time, when I mount an nfs share, I see 6-7 blocked packets in the client's firewall log. These packets come from and to random tcp ports, but they are the same at every mount.
      For example, after this command:



      mount -t nfs server:/logs /logs


      I see in the firewall log/journalctl output:



      nov 16 15:46:22 machine kernel: [UFW BLOCK] IN=wlp1s0 OUT= MAC=<mac addresses> SRC=<NFS server's IP> DST=<client's IP> LEN=60 TOS=0x00 PREC=0x00 TTL=63 ID=34612 DF PROTO=TCP SPT=695 DPT=37123 WINDOW=29200 RES=0x00 SYN URGP=0i


      repeated 6 times.
      After umounting, then mounting it again, I see:



      nov 16 16:16:18 machine kernel: [UFW BLOCK] IN=wlp1s0 OUT= MAC=<mac addresses> SRC=<NFS server's IP> DST=<client's IP> LEN=60 TOS=0x00 PREC=0x00 TTL=63 ID=54001 DF PROTO=TCP SPT=915 DPT=37123 WINDOW=29200 RES=0x00 SYN URGP=0


      repeated 6 times again.
      Etc.



      First of all: why? What the NFS server wants from my client? And how can I fix it (to use the same port every time)?






      linux networking firewall mount nfs







      share|improve this question













      Could you help me, how can I prevent this?
      Every time, when I mount an nfs share, I see 6-7 blocked packets in the client's firewall log. These packets come from and to random tcp ports, but they are the same at every mount.
      For example, after this command:



      mount -t nfs server:/logs /logs


      I see in the firewall log/journalctl output:



      nov 16 15:46:22 machine kernel: [UFW BLOCK] IN=wlp1s0 OUT= MAC=<mac addresses> SRC=<NFS server's IP> DST=<client's IP> LEN=60 TOS=0x00 PREC=0x00 TTL=63 ID=34612 DF PROTO=TCP SPT=695 DPT=37123 WINDOW=29200 RES=0x00 SYN URGP=0i


      repeated 6 times.
      After umounting, then mounting it again, I see:



      nov 16 16:16:18 machine kernel: [UFW BLOCK] IN=wlp1s0 OUT= MAC=<mac addresses> SRC=<NFS server's IP> DST=<client's IP> LEN=60 TOS=0x00 PREC=0x00 TTL=63 ID=54001 DF PROTO=TCP SPT=915 DPT=37123 WINDOW=29200 RES=0x00 SYN URGP=0


      repeated 6 times again.
      Etc.



      First of all: why? What the NFS server wants from my client? And how can I fix it (to use the same port every time)?






      linux networking firewall mount nfs




      linux networking firewall mount nfs






      share|improve this question













      share|improve this question











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      share|improve this question










      asked 2 days ago









      user895804

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