서버 DHCP 서버 끊김 현상

안녕하세요. 우분투 16.04LTS를 배워가면서 DHCP 서버를 구축해 사용하고 있는 학생입니다.

 

내장 유선 랜카드 1(WAN)

USB 유선 랜카드 1(LAN) (enx00e04c6807a7)

 

 

하지만 몇 시간이 지나면 잘 사용하던 서브컴에서  인터넷 연결이 끊겨버립니다.

 

# systemctl status isc-dhcp-server

● isc-dhcp-server.service - ISC DHCP IPv4 server
   Loaded: loaded (/lib/systemd/system/isc-dhcp-server.service; enabled; vendor preset: enabled)
   Active: active (running) since 화 2017-09-12 11:48:15 KST; 5h 16min ago
     Docs: man:dhcpd(8)
 Main PID: 10798 (dhcpd)
   CGroup: /system.slice/isc-dhcp-server.service
           └─10798 dhcpd -user dhcpd -group dhcpd -f -4 -pf /run/dhcp-server/dhcpd.pid -cf /etc/dhcp/dhcpd.conf enx00e04c6807a7

 9월 12 11:48:49 DATACTR-U16ADM dhcpd[10798]: DHCPACK on 192.168.0.2 to xx:xx:xx:xx (SUB_COMPUTER) via enx00e04c6807a7
 9월 12 11:48:49 DATACTR-U16ADM dhcpd[10798]: reuse_lease: lease age 0 (secs) under 25% threshold, reply with unaltered, existing lease
 9월 12 11:48:49 DATACTR-U16ADM dhcpd[10798]: DHCPREQUEST for 192.168.0.2 (192.168.0.1) from xx:xx:xx:xx (SUB_COMPUTER) via enx00e04c6807a7
 9월 12 11:48:49 DATACTR-U16ADM dhcpd[10798]: DHCPACK on 192.168.0.2 to xx:xx:xx:xx via enx00e04c6807a7
 9월 12 12:18:49 DATACTR-U16ADM dhcpd[10798]: DHCPREQUEST for 192.168.0.2 from xx:xx:xx:xx via enx00e04c6807a7
 9월 12 12:18:49 DATACTR-U16ADM dhcpd[10798]: DHCPACK on 192.168.0.2 to xx:xx:xx:xx (SUB_COMPUTER) via enx00e04c6807a7
 9월 12 12:48:49 DATACTR-U16ADM dhcpd[10798]: Wrote 2 leases to leases file.
 9월 12 12:48:49 DATACTR-U16ADM dhcpd[10798]: DHCPREQUEST for 192.168.0.2 from xx:xx:xx:xx (SUB_COMPUTER) via enx00e04c6807a7
 9월 12 12:48:49 DATACTR-U16ADM dhcpd[10798]: DHCPACK on 192.168.0.2 to xx:xx:xx:xx (SUB_COMPUTER) via enx00e04c6807a7
 9월 12 14:23:11 DATACTR-U16ADM dhcpd[10798]: receive_packet failed on enx00e04c6807a7: Network is down

 

14시 23분에 갑자기 USB 랜카드(서브 컴과 연결되어 있음)에서 패킷을 받을 수 없다네요...

 

 

car /var/log/syslog

 

Sep 12 14:23:11 SERVER kernel: [64638.640476] usb 2-4: USB disconnect, device number 8
Sep 12 14:23:11 SERVER kernel: [64638.640652] r8152 2-4:1.0 enx00e04c6807a7: Stop submitting intr, status -108
Sep 12 14:23:11 SERVER avahi-daemon[876]: Interface enx00e04c6807a7.IPv6 no longer relevant for mDNS.
Sep 12 14:23:11 SERVER avahi-daemon[876]: Leaving mDNS multicast group on interface enx00e04c6807a7.IPv6 with address xxxx::xxx:xxxx:xxxx:xxx.
Sep 12 14:23:11 SERVER avahi-daemon[876]: Interface enx00e04c6807a7.IPv4 no longer relevant for mDNS.
Sep 12 14:23:11 SERVER avahi-daemon[876]: Leaving mDNS multicast group on interface enx00e04c6807a7.IPv4 with address 192.168.0.1.
Sep 12 14:23:11 SERVER avahi-daemon[876]: Withdrawing address record for xxxx::xxx:xxxx:xxxx:xxx on enx00e04c6807a7.
Sep 12 14:23:11 SERVER avahi-daemon[876]: Withdrawing address record for 192.168.0.1 on enx00e04c6807a7.
Sep 12 14:23:11 SERVER dhcpd[10798]: receive_packet failed on enx00e04c6807a7: Network is down
Sep 12 14:23:11 SERVER systemd[1]: Stopping ifup for enx00e04c6807a7...
Sep 12 14:23:11 SERVER NetworkManager[850]: <error> [1505193791.2564] platform-linux: do-change-link[9]: failure changing link: failure 19 (그런 장치가 없음)
Sep 12 14:23:11 SERVER NetworkManager[850]: <warn>  [1505193791.2564] device (enx00e04c6807a7): failed to disable userspace IPv6LL address handling
Sep 12 14:23:11 SERVER NetworkManager[850]: <info>  [1505193791.2570] devices removed (path: /sys/devices/pci0000:00/0000:00:14.0/usb2/2-4/2-4:1.0/net/enx00e04c6807a7, iface: enx00e04c6807a7)
Sep 12 14:23:11 SERVER NetworkManager[850]: <info>  [1505193791.2574] get unmanaged devices count: 1
Sep 12 14:23:11 SERVER ifdown[14220]: Cannot find device "enx00e04c6807a7"
Sep 12 14:23:11 SERVER ifdown[14220]: message repeated 2 times: [ Cannot find device "enx00e04c6807a7"]
Sep 12 14:23:11 SERVER systemd[1]: Stopped ifup for enx00e04c6807a7.
Sep 12 14:23:11 SERVER kernel: [64638.870535] usb 2-4: new SuperSpeed USB device number 9 using xhci_hcd
Sep 12 14:23:11 SERVER kernel: [64638.882975] usb 2-4: New USB device found, idVendor=0bda, idProduct=8153
Sep 12 14:23:11 SERVER kernel: [64638.882980] usb 2-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Sep 12 14:23:11 SERVER kernel: [64638.882983] usb 2-4: Product: USB 10/100/1000 LAN
Sep 12 14:23:11 SERVER kernel: [64638.882986] usb 2-4: Manufacturer: Realtek
Sep 12 14:23:11 SERVER kernel: [64638.882988] usb 2-4: SerialNumber: 00E04C6807A7
Sep 12 14:23:11 SERVER kernel: [64638.990763] usb 2-4: reset SuperSpeed USB device number 9 using xhci_hcd
Sep 12 14:23:11 SERVER kernel: [64639.050273] r8152 2-4:1.0 eth0: v1.08.9
Sep 12 14:23:11 SERVER NetworkManager[850]: <warn>  [1505193791.6470] device (eth0): failed to find device 10 'eth0' with udev
Sep 12 14:23:11 SERVER NetworkManager[850]: <info>  [1505193791.6495] manager: (eth0): new Ethernet device (/org/freedesktop/NetworkManager/Devices/9)
Sep 12 14:23:11 SERVER mtp-probe: checking bus 2, device 9: "/sys/devices/pci0000:00/0000:00:14.0/usb2/2-4"
Sep 12 14:23:11 SERVER mtp-probe: bus: 2, device: 9 was not an MTP device
Sep 12 14:23:12 SERVER kernel: [64640.111636] r8152 2-4:1.0 enx00e04c6807a7: renamed from eth0
Sep 12 14:23:12 SERVER NetworkManager[850]: <info>  [1505193792.7171] device (eth0): interface index 10 renamed iface from 'eth0' to 'enx00e04c6807a7'
Sep 12 14:23:12 SERVER systemd[1]: Started ifup for enx00e04c6807a7.
Sep 12 14:23:12 SERVER NetworkManager[850]: <info>  [1505193792.7425] devices added (path: /sys/devices/pci0000:00/0000:00:14.0/usb2/2-4/2-4:1.0/net/enx00e04c6807a7, iface: enx00e04c6807a7)
Sep 12 14:23:12 SERVER NetworkManager[850]: <info>  [1505193792.7435] locking wired connection setting
Sep 12 14:23:12 SERVER NetworkManager[850]: <info>  [1505193792.7437] get unmanaged devices count: 2
Sep 12 14:23:12 SERVER systemd[1]: Found device USB_10_100_1000_LAN.
Sep 12 14:23:12 SERVER avahi-daemon[876]: Joining mDNS multicast group on interface enx00e04c6807a7.IPv4 with address 192.168.0.1.
Sep 12 14:23:12 SERVER avahi-daemon[876]: New relevant interface enx00e04c6807a7.IPv4 for mDNS.
Sep 12 14:23:12 SERVER kernel: [64640.193814] IPv6: ADDRCONF(NETDEV_UP): enx00e04c6807a7: link is not ready
Sep 12 14:23:12 SERVER avahi-daemon[876]: Registering new address record for 192.168.0.1 on enx00e04c6807a7.IPv4.
Sep 12 14:23:14 SERVER ModemManager[801]: <info>  Couldn't find support for device at '/sys/devices/pci0000:00/0000:00:14.0/usb2/2-4': not supported by any plugin

 

 

USB 랜카드를 분리한 적이 없는데 디스커넥트되었다 해서 원인이 뭔지 모르겠습니다.

 

이런 상태에서 서브컴에서 ping도 안날려지지만  192.168.0.1(서버)의 웹서버는 접속이 가능했습니다. 외부 인터넷은 연결이 안되구요.. 

 

systemctl restart isc-dhcp-server 하고 서브컴의 랜선을 뽑았다가 다시 꼽으면 몇초 뒤 다시 인터넷 연결이 됩니다.

 

systemctl restart isc-dhcp-server 이 명령어만 해서는 다시 인터넷 연결이 안되고 랜선을 다시 꼽아야 되더군요...

 

 

 

 

로그를 보면 NIC 명칭이 eth0이란게 나오는데 저는 처음부터 ifconfig에 eth0, eth1이렇게 나오는게 아니라 enx00e04c6807a7 이런식으로 이름이 바뀌어 나타나더라구요.. 그래서 dhcpd.conf나 /etc/dhcp/interfaces/ 에서도 eth0, eth1이라고 적질 않았습니다. 관련이 있는지 모르겠네요....

 

 

고수님들 소중한 답변 부탁드립니다.