H3C-GRE-MIB

Description: H3C MIB for Generic Routing Encapsulation (GRE) tunnel configuration and monitoring including tunnel endpoints.

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H3C-GRE-MIB is an H3C (Huawei-3Com) vendor-specific MIB that manages Generic Routing Encapsulation (GRE) tunnel configuration on H3C routing platforms, referencing the GRE key and checksum mechanisms defined in RFC 2784 and RFC 2890. Its single h3cGreTable, indexed by the standard ifIndex from IF-MIB, exposes h3cGreKeyValue (the configured GRE key value) alongside h3cGreKey and h3cGreChecksum enable/disable flags that control whether the GRE key field and checksum are used on that tunnel interface. Because GRE key and checksum settings must match on both tunnel endpoints, this MIB is useful for confirming that a tunnel interface's key/checksum configuration is consistent with its remote peer before diagnosing a tunnel that is up at the interface level but not passing traffic. It depends on the underlying GRE tunnel interface already being created (via ifIndex) and is deployed on H3C routers running GRE tunnels for site-to-site connectivity, and this H3C-GRE-MIB MIB is what network engineers consult to verify per-tunnel key and checksum state.

An operator polls h3cGreKeyValue and h3cGreKey for a GRE tunnel's ifIndex and compares it against the configuration expected on the remote endpoint; a mismatched h3cGreKeyValue or a h3cGreKey set to disable when the peer expects a key would explain why GRE-encapsulated traffic is silently dropped despite the tunnel interface showing up/up.

Generic Routing Encapsulation tunnel configuration and state monitoring.