---
layout: docs
page_title: Gossip parameters for Consul agent configuration files
description: >-
  Use agent configuration files to assign attributes to agents and configure multiple agents at once. Learn about agent configuration file parameters and formatting with this reference page and sample code.
---

# Gossip parameters for Consul agent configuration files

The page provides reference information for gossip parameters in a Consul agent configuration file.

## Gossip parameters

- `gossip_lan` - **(Advanced)** This object contains a
  number of sub-keys which can be set to tune the LAN gossip communications. These
  are only provided for users running especially large clusters that need fine tuning
  and are prepared to spend significant effort correctly tuning them for their environment
  and workload. **Tuning these improperly can cause Consul to fail in unexpected
  ways**. The default values are appropriate in almost all deployments.

  - `gossip_nodes` - The number of random nodes to send
    gossip messages to per gossip_interval. Increasing this number causes the gossip
    messages to propagate across the cluster more quickly at the expense of increased
    bandwidth. The default is 3.

  - `gossip_interval` - The interval between sending
    messages that need to be gossiped that haven't been able to piggyback on probing
    messages. If this is set to zero, non-piggyback gossip is disabled. By lowering
    this value (more frequent) gossip messages are propagated across the cluster
    more quickly at the expense of increased bandwidth. The default is 200ms.

  - `probe_interval` - The interval between random
    node probes. Setting this lower (more frequent) will cause the cluster to detect
    failed nodes more quickly at the expense of increased bandwidth usage. The default
    is 1s.

  - `probe_timeout` - The timeout to wait for an ack
    from a probed node before assuming it is unhealthy. This should be at least the
    99-percentile of RTT (round-trip time) on your network. The default is 500ms
    and is a conservative value suitable for almost all realistic deployments.

  - `retransmit_mult` - The multiplier for the number
    of retransmissions that are attempted for messages broadcasted over gossip. The
    number of retransmits is scaled using this multiplier and the cluster size. The
    higher the multiplier, the more likely a failed broadcast is to converge at the
    expense of increased bandwidth. The default is 4.

  - `suspicion_mult` - The multiplier for determining
    the time an inaccessible node is considered suspect before declaring it dead.
    The timeout is scaled with the cluster size and the probe_interval. This allows
    the timeout to scale properly with expected propagation delay with a larger cluster
    size. The higher the multiplier, the longer an inaccessible node is considered
    part of the cluster before declaring it dead, giving that suspect node more time
    to refute if it is indeed still alive. The default is 4.

- `gossip_wan` - **(Advanced)** This object contains a
  number of sub-keys which can be set to tune the WAN gossip communications. These
  are only provided for users running especially large clusters that need fine tuning
  and are prepared to spend significant effort correctly tuning them for their environment
  and workload. **Tuning these improperly can cause Consul to fail in unexpected
  ways**. The default values are appropriate in almost all deployments.

  - `gossip_nodes` - The number of random nodes to send
    gossip messages to per gossip_interval. Increasing this number causes the gossip
    messages to propagate across the cluster more quickly at the expense of increased
    bandwidth. The default is 4.

  - `gossip_interval` - The interval between sending
    messages that need to be gossiped that haven't been able to piggyback on probing
    messages. If this is set to zero, non-piggyback gossip is disabled. By lowering
    this value (more frequent) gossip messages are propagated across the cluster
    more quickly at the expense of increased bandwidth. The default is 500ms.

  - `probe_interval` - The interval between random
    node probes. Setting this lower (more frequent) will cause the cluster to detect
    failed nodes more quickly at the expense of increased bandwidth usage. The default
    is 5s.

  - `probe_timeout` - The timeout to wait for an ack
    from a probed node before assuming it is unhealthy. This should be at least the
    99-percentile of RTT (round-trip time) on your network. The default is 3s
    and is a conservative value suitable for almost all realistic deployments.

  - `retransmit_mult` - The multiplier for the number
    of retransmissions that are attempted for messages broadcasted over gossip. The
    number of retransmits is scaled using this multiplier and the cluster size. The
    higher the multiplier, the more likely a failed broadcast is to converge at the
    expense of increased bandwidth. The default is 4.

  - `suspicion_mult` - The multiplier for determining
    the time an inaccessible node is considered suspect before declaring it dead.
    The timeout is scaled with the cluster size and the probe_interval. This allows
    the timeout to scale properly with expected propagation delay with a larger cluster
    size. The higher the multiplier, the longer an inaccessible node is considered
    part of the cluster before declaring it dead, giving that suspect node more time
    to refute if it is indeed still alive. The default is 6.