My Uni provided me two hostnames and static IPs for two interfaces on my Fedora Server 23. My idea is to use one hostname for production and another for dev branches. It should work as: bio-db.uni.edu on interface eno2 with xxx.xxx.86.24 IP and bio-db-dev.uni.edu on eno1 with with xxx.xxx.86.64 IP. Server is CherryPy (two instances bound to given static IPs)
I ran one interface eno2 for months now, but when I opened up second interface with ifconfig eno1 up, I received message from IT department that there is a conflict:
Network access for xx:xx:xx:xx:xx:71 (bio-db.uni.edu) has been disabled at 04/26/16 15:34:54: Reason: Host using incorrect IP address MAC xx:xx:xx:xx:xx:71 IP xxx.xxx.xxx.64 found in rtr30 cache Switch: switch.uni.edu Port: 52051 It appears a bit random: sometime eno1 get disabled, sometimes eno2, but they always get these two IPs mixed up.
How I can debug this? I am in touch with IT people, but also want to know if that is something my serve is doing wrong. Which logs might help me?
When IPs are allocated by DHCP, hosts become accessible as supposed, my ifconfig looks like that right after I bring interfaces up:
# uname -a Linux bio-db.uni.edu 4.3.5-300.fc23.x86_64 #1 SMP Mon Feb 1 03:18:41 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux # ifconfig eno1 <-- is 'bio-db-dev.uni.edu' eno1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet xxx.xxx.86.64 netmask 255.255.254.0 broadcast xxx.xxx.87.255 inet6 __IPV6__ prefixlen 64 scopeid 0x20<link> ether xx:xx:xx:xx:xx:70 txqueuelen 1000 (Ethernet) RX packets 63597 bytes 10057016 (9.5 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 2504 bytes 1899384 (1.8 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 device interrupt 16 # ifconfig eno2 <-- is 'bio-db.uni.edu' eno2: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet xxx.xxx.86.24 netmask 255.255.254.0 broadcast xxx.xxx.87.255 inet6 __IPV6__ prefixlen 64 scopeid 0x20<link> ether xx:xx:xx:xx:xx:71 txqueuelen 1000 (Ethernet) RX packets 11575 bytes 1834587 (1.7 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 417 bytes 68578 (66.9 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 device interrupt 17 Added ip address and ip route listing
# ip address 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eno1: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000 link/ether 40:f2:e9:bd:97:70 brd ff:ff:ff:ff:ff:ff inet xxx.xxx.86.64/23 brd xxx.xxx.87.255 scope global eno1 valid_lft forever preferred_lft forever inet6 fe80::42f2:e9ff:febd:9770/64 scope link valid_lft forever preferred_lft forever 3: eno2: <BROADCAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000 link/ether 40:f2:e9:bd:97:71 brd ff:ff:ff:ff:ff:ff inet xxx.xxx.86.24/23 brd xxx.xxx.87.255 scope global eno2 valid_lft forever preferred_lft forever inet6 fe80::42f2:e9ff:febd:9771/64 scope link valid_lft forever preferred_lft forever 4: eno3: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN group default qlen 1000 link/ether 40:f2:e9:bd:97:72 brd ff:ff:ff:ff:ff:ff 5: eno4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000 link/ether 40:f2:e9:bd:97:73 brd ff:ff:ff:ff:ff:ff inet 192.168.0.40/24 brd 192.168.0.255 scope global eno4 valid_lft forever preferred_lft forever inet6 fe80::42f2:e9ff:febd:9773/64 scope link valid_lft forever preferred_lft forever 6: ens1f0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000 link/ether 90:e2:ba:b6:f7:34 brd ff:ff:ff:ff:ff:ff 7: ens1f1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000 link/ether 90:e2:ba:b6:f7:35 brd ff:ff:ff:ff:ff:ff 8: enp0s20u13u5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN group default qlen 1000 link/ether 42:f2:e9:bd:97:77 brd ff:ff:ff:ff:ff:ff inet 169.254.95.120/24 brd 169.254.95.255 scope link dynamic enp0s20u13u5 valid_lft 541sec preferred_lft 541sec inet6 fe80::40f2:e9ff:febd:9777/64 scope link valid_lft forever preferred_lft forever 9: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000 link/ether 52:54:00:d8:5d:36 brd ff:ff:ff:ff:ff:ff inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 valid_lft forever preferred_lft forever 10: virbr0-nic: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue master virbr0 state DOWN group default qlen 500 link/ether 52:54:00:d8:5d:36 brd ff:ff:ff:ff:ff:ff # ip route default via xxx.xxx.86.1 dev eno2 proto static metric 100 default via xxx.xxx.86.1 dev eno1 proto static metric 101 xxx.xxx.86.0/23 dev eno2 proto kernel scope link src xxx.xxx.86.24 metric 100 xxx.xxx.86.0/23 dev eno1 proto kernel scope link src xxx.xxx.86.64 metric 101 xxx.xxx.253.244 via xxx.xxx.86.1 dev eno2 proto dhcp metric 100 169.254.95.0/24 dev enp0s20u13u5 proto kernel scope link src 169.254.95.120 metric 100 192.168.0.0/24 dev eno4 proto kernel scope link src 192.168.0.40 metric 100 192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1 
ip addressandip route... and update your system.