View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0017413 | CentOS-8 | NetworkManager | public | 2020-05-28 20:34 | 2020-05-28 20:34 |
| Reporter | dlimadaum | Assigned To | |||
| Priority | high | Severity | block | Reproducibility | always |
| Status | new | Resolution | open | ||
| Product Version | 8.1.1911 | ||||
| Summary | 0017413: Impossibile to use /31 address | ||||
| Description | Migrating some servers from 7 to 8 I discovered a problem using /31 address on network interface. Same configuration of the interface but it not start up, and logging in via console and trying to star the interface via ifup it stuck for a while and then exit with error. "Connection activation failed: IP configuration could not be reserved (no available address, timeout, etc). Tried also with the network-script and disabling the management of NetworkManager result in an error "Error adding default gateway <ip-of-the-gateway> for <interface-name> It seems that the script set the broadcast address but in a /31 configuration no broadcast and no network address exist...so when it try to add the default route the gateway is the broadcast address... If I configure the interface via ip command, it work fine without errors, because it not specify a broadcast address in the interface so the ip route add work without issue: Interface configured with ifup: 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 7a:f1:2e:3c:d0:da brd ff:ff:ff:ff:ff:ff inet 46.20.84.242/31 brd 46.20.84.243 scope global eth0 valid_lft forever preferred_lft forever inet6 fe80::78f1:2eff:fe3c:d0da/64 scope link valid_lft forever preferred_lft forever Inteface configured with ip command: 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 link/ether 7a:f1:2e:3c:d0:da brd ff:ff:ff:ff:ff:ff inet 46.20.84.242/31 scope global eth0 valid_lft forever preferred_lft forever inet6 fe80::78f1:2eff:fe3c:d0da/64 scope link valid_lft forever preferred_lft forever I think that also NetworkManager make the same mistake. The strange thing is that this configuration is working fine on a Centos7... The only way to put a patch is to configure the interface with an external script at boot and disable completely NetworkManager and network-script. | ||||
| Steps To Reproduce | Configure a /31 address on the interface. Ifup interface-name | ||||
| Additional Information | To try with the ip command: ip link set <interface-name> up ip add add <ip-address>/31 dev eth0 ip route add default via <gateway> dev eth0 | ||||
| Tags | No tags attached. | ||||
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2020-05-28 20:34 | dlimadaum | New Issue |
