ocf_heartbeat_IPaddr2 - Man Page

IPaddr2 [start | stop | status | monitor | meta-data | validate-all]

This Linux-specific resource manages IP alias IP addresses. It can add an IP alias, or remove one. In addition, it can implement Cluster Alias IP functionality if invoked as a clone resource.

If used as a clone, "shared address with a trivial, stateless (autonomous) load-balancing/mutual exclusion on ingress" mode gets applied (as opposed to "assume resource uniqueness" mode otherwise). For that, Linux firewall (kernel and userspace) is assumed, and since recent distributions are ambivalent in plain "iptables" command to particular back-end resolution, "iptables-legacy" (when present) gets prioritized so as to avoid incompatibilities (note that respective ipt_CLUSTERIP firewall extension in use here is, at the same time, marked deprecated, yet said "legacy" layer can make it workable, literally, to this day) with "netfilter" one (as in "iptables-nft"). In that case, you should explicitly set clone-node-max >= 2, and/or clone-max < number of nodes. In case of node failure, clone instances need to be re-allocated on surviving nodes. This would not be possible if there is already an instance on those nodes, and clone-node-max=1 (which is the default).

When the specified IP address gets assigned to a respective interface, the resource agent sends unsolicited ARP (Address Resolution Protocol, IPv4) or NA (Neighbor Advertisement, IPv6) packets to inform neighboring machines about the change. This functionality is controlled for both IPv4 and IPv6 by shared 'arp_*' parameters.

ip

The IPv4 (dotted quad notation) or IPv6 address (colon hexadecimal notation) example IPv4 "192.168.1.1". example IPv6 "2001:db8:DC28:0:0:FC57:D4C8:1FFF".

(unique, required, string, no default)

nic

The base network interface on which the IP address will be brought online. If left empty, the script will try and determine this from the routing table.

Do NOT specify an alias interface in the form eth0:1 or anything here; rather, specify the base interface only. If you want a label, see the iflabel parameter.

Prerequisite:

There must be at least one static IP address, which is not managed by the cluster, assigned to the network interface. If you can not assign any static IP address on the interface, modify this kernel parameter:

sysctl -w net.ipv4.conf.all.promote_secondaries=1 # (or per device)

(optional, string, no default)

cidr_netmask

The netmask for the interface in CIDR format (e.g., 24 and not 255.255.255.0)

If unspecified, the script will also try to determine this from the routing table.

(optional, string, no default)

broadcast

Broadcast address associated with the IP. It is possible to use the special symbols '+' and '-' instead of the broadcast address. In this case, the broadcast address is derived by setting/resetting the host bits of the interface prefix.

(optional, string, no default)

iflabel

You can specify an additional label for your IP address here. This label is appended to your interface name.

The kernel allows alphanumeric labels up to a maximum length of 15 characters including the interface name and colon (e.g. eth0:foobar1234)

A label can be specified in nic parameter but it is deprecated. If a label is specified in nic name, this parameter has no effect.

(optional, string, no default)

lvs_support

Enable support for LVS Direct Routing configurations. In case a IP address is stopped, only move it to the loopback device to allow the local node to continue to service requests, but no longer advertise it on the network.

Notes for IPv6: It is not necessary to enable this option on IPv6. Instead, enable 'lvs_ipv6_addrlabel' option for LVS-DR usage on IPv6.

(optional, boolean, default false)

lvs_ipv6_addrlabel

Enable adding IPv6 address label so IPv6 traffic originating from the address's interface does not use this address as the source. This is necessary for LVS-DR health checks to realservers to work. Without it, the most recently added IPv6 address (probably the address added by IPaddr2) will be used as the source address for IPv6 traffic from that interface and since that address exists on loopback on the realservers, the realserver response to pings/connections will never leave its loopback. See RFC3484 for the detail of the source address selection.

See also 'lvs_ipv6_addrlabel_value' parameter.

(optional, boolean, default true)

lvs_ipv6_addrlabel_value

Specify IPv6 address label value used when 'lvs_ipv6_addrlabel' is enabled. The value should be an unused label in the policy table which is shown by 'ip addrlabel list' command. You would rarely need to change this parameter.

(optional, integer, default 99)

mac

Set the interface MAC address explicitly. Currently only used in case of the Cluster IP Alias. Leave empty to chose automatically.

(optional, string, no default)

clusterip_hash

Specify the hashing algorithm used for the Cluster IP functionality.

(optional, string, default "sourceip-sourceport")

unique_clone_address

If true, add the clone ID to the supplied value of IP to create a unique address to manage

(optional, boolean, default false)

arp_interval

Specify the interval between unsolicited ARP (IPv4) or NA (IPv6) packets in milliseconds.

This parameter is deprecated and used for the backward compatibility only. It is effective only for the send_arp binary which is built with libnet, and send_ua for IPv6. It has no effect for other arp_sender.

(optional, integer, default 200)

arp_count

Number of unsolicited ARP (IPv4) or NA (IPv6) packets to send at resource initialization.

(optional, integer, default 5)

arp_count_refresh

For IPv4, number of unsolicited ARP packets to send during resource monitoring. Doing so helps mitigate issues of stuck ARP caches resulting from split-brain situations.

(optional, integer, default 0)

arp_bg

Whether or not to send the ARP (IPv4) or NA (IPv6) packets in the background. The default is true for IPv4 and false for IPv6.

(optional, string, no default)

arp_sender

For IPv4, the program to send ARP packets with on start. Available options are: - send_arp: default - ipoibarping: default for infiniband interfaces if ipoibarping is available - iputils_arping: use arping in iputils package - libnet_arping: use another variant of arping based on libnet

(optional, string, no default)

send_arp_opts

For IPv4, extra options to pass to the arp_sender program. Available options are vary depending on which arp_sender is used.

A typical use case is specifying '-A' for iputils_arping to use ARP REPLY instead of ARP REQUEST as Gratuitous ARPs.

(optional, string, no default)

flush_routes

Flush the routing table on stop. This is for applications which use the cluster IP address and which run on the same physical host that the IP address lives on. The Linux kernel may force that application to take a shortcut to the local loopback interface, instead of the interface the address is really bound to. Under those circumstances, an application may, somewhat unexpectedly, continue to use connections for some time even after the IP address is deconfigured. Set this parameter in order to immediately disable said shortcut when the IP address goes away.

(optional, boolean, default false)

run_arping

For IPv4, whether or not to run arping for collision detection check.

(optional, string, default "false")

nodad

For IPv6, do not perform Duplicate Address Detection when adding the address.

(optional, string, default "false")

noprefixroute

Use noprefixroute flag (see 'man ip-address').

(optional, string, default "false")

preferred_lft

For IPv6, set the preferred lifetime of the IP address. This can be used to ensure that the created IP address will not be used as a source address for routing. Expects a value as specified in section 5.5.4 of RFC 4862.

(optional, string, default "forever")

network_namespace

Specifies the network namespace to operate within. The namespace must already exist, and the interface to be used must be within the namespace.

(optional, string, no default)

This resource agent supports the following actions (operations):

start

Starts the resource. Suggested minimum timeout: 20s.

stop

Stops the resource. Suggested minimum timeout: 20s.

status

Performs a status check. Suggested minimum timeout: 20s. Suggested interval: 10s.

monitor

Performs a detailed status check. Suggested minimum timeout: 20s. Suggested interval: 10s.

meta-data

Retrieves resource agent metadata (internal use only). Suggested minimum timeout: 5s.

validate-all

Performs a validation of the resource configuration. Suggested minimum timeout: 20s.

The following is an example configuration for a IPaddr2 resource using the crm(8) shell:

primitive p_IPaddr2 ocf:heartbeat:IPaddr2 \
  params \
    ip=string \
  op monitor depth="0" timeout="20s" interval="10s"

The following is an example configuration for a IPaddr2 resource using pcs(8)

pcs resource create p_IPaddr2 ocf:heartbeat:IPaddr2 \
  ip=string \
  op monitor OCF_CHECK_LEVEL="0" timeout="20s" interval="10s"

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