Defaults and Timers

This page is dedicated to showing various default timer and metric values for a wide range of protocols.

 Technology or Protocol Vendor/Platform Feature Default Value/Metric Comment
QoS – CB-WFQ Cisco max-reserved-bandwith percentage 75% Use max-reserved-bandwidth to change
BGP Cisco BGP Hello Timer 60 seconds n/a
QoS – LLQ Cisco Priority queue policer burst rate 20 percent This is the default if not specified
QoS – WRED Cisco Exponential Weighting constant 9 Results in 0.2% of the new average being account for at each average queue depth calculation.
OSPF Cisco Priority 1 Used to elect DR and BDR with higher being preferred
OSPF Cisco Reflood Timer 30 minutes A router will reflood LSAs every 30 minutes after incrementing the sequence number by 1
OSPF Cisco maximum-paths 4 The number of equal cost OSPF paths that can be added to the routing table. OSPF doesn’t support unequal cost load balancing.
OSPF Cisco Reference Bandwidth 100Mbps Used in metric calculation (metric = Reference_Bandwidth/ Interface_Bandwidth) . Change the reference bandwidth using auto-cost reference-bandwidth (IOS)
ISIS Cisco Metric 10 n/a
OSPF Cisco Summary Route Metric Lowest metric of all routes that it is advertising This pertains to inter-area summarisation using the area range [cost ] command.
OSPF Cisco default-information originate metric


default metric for stub area default routes.

1 If not specified, the default information originate  IOS command (used to send a type 5 LSA into an OSPF area as a default) applies an OSPF cost of 1 to the default route. The default metric-type used is 2.
QoS – Shaping Cisco IOS Tc 125ms Not the default for all shaping tools, but the default for many.
QoS – Shaping Cisco IOS Class Based shaping default queuing method FIFO WFQ, LLQ and CB-WFQ are support but FIFO is the default.
QoS – Shaping Cisco IOS Be (Burst Excess) Bc value If not specified the Be value will be equal to the Bc value
QoS – Shaping Cisco IOS Bc (Burst commit) when Shaping speed is less than or equal to 320 kbps 8000bits n/a
QoS – Shaping Cisco IOS Bc (Burst commit) when Shaping speed is over 320 kbps Tc is set to 25ms and calculated Bc using bc = Tc * CIR n/a
QoS – Policing Cisco IOS Bc The larger (in bytes) of 1500 or CIR/32 CIR is measured in bps
QoS – Policing Cisco IOS Be for single rate, two colour policer 0 bytes n/a
QoS – Policing Cisco IOS Be for single rate, three colour policer Equal to the Bc value in bytes n/a
QoS – Policing Cisco IOS Be for dual rate, three colour policer The larger (in bytes) of 1500 or PIR/32 PIR is measured in bps
LDP Cisco IPv4 Transport address LDP Router ID (which is in turn the highest loopback ID) Set using mpls ldp router-id IOS command.
PIMv2 Cisco Designated Forwarder election on Multi-access networks Higher IP wins if routing protocol AD then metric are a tie. n/a
PIM-SM Cisco Bootstrap BSR Priority Range 0 – 255. Default 0. Highest wins.
PIM-SM Cisco Bootstrap start Timer 130s. Started on Bootstrap is configured.
PIM-SM Cisco Bootstrap timer If router deems itself to be the BSR is sentds a Bootstrap message every 60 seconds.
PIM-SM Cisco Bootstrap Candidate-RP Priority Range 0-255
PIM-SM Cisco Auto-RP RP election Highest IP wins
PIM-SM Cisco Join/Prune periodic keepalives 60 seconds.
PIM-SM  Cisco Join/Prune keepalives Hello x 3 (default 180 seconds)