Next hop inaccessible-linux-False

error
health-checks
false
linux
Next hop inaccessible-linux-False
0

#1

Next hop inaccessible-linux-False

Vendor: linux

OS: False

Description:
Indeni will review the routing table and identify when a next hop router is showing as FAILED or INCOMPLETE in the ARP table.

Remediation Steps:
Determine why the next hops are not responding.

How does this work?
By running the command “netstat -rn” the routes are retrieved.

Why is this important?
It is important that the routing is configured the same for all cluster members of the same cluster. Otherwise there can be downtime in the event of a failover.

Without Indeni how would you find this?
An administrator could login and manually run the command.

linux-os-netstat_rn

#! META
name: linux-os-netstat_rn
description: Get routing table using "netstat -rn"
type: monitoring
monitoring_interval: 1 minute
requires:
    or:
        -
            linux-based: "true"
        -
            linux-busybox: "true"
    and:
        -
            vendor:
                neq: "checkpoint"
        -
            vendor:
                neq: "f5"

#! COMMENTS
static-routing-table:
    why: |
        It is important that the routing is configured the same for all cluster members of the same cluster. Otherwise there can be downtime in the event of a failover.
    how: |
        By running the command "netstat -rn" the routes are retrieved.
    without-indeni: |
        An administrator could login and manually run the command.
    can-with-snmp: true
    can-with-syslog: false
    vendor-provided-management: |
        Listing static routes is only available from the command line interface or via SNMP.

connected-networks-table:
    why: |
        It is important that the connected interfaces is configured the same, for all cluster members of the same cluster. Otherwise there can be downtime in the event of a failure.
    how: |
          By running the command "netstat -rn" the routes are retrieved.
    without-indeni: |
        An administrator could login and manually run the command.
    can-with-snmp: true
    can-with-syslog: false
    vendor-provided-management: |
        Listing routes for directly connected interfaces is only available from the command line interface, or SNMP.

#! REMOTE::SSH
${nice-path} -n 15 netstat -rn

#! PARSER::AWK

# Function to calculate number of binary 1s in a decimal number
function count1s(N) {
	r = ""                    # initialize result to empty (not 0)
	while(N != 0){            # as long as number still has a value
		r = ((N%2)?"1":"0") r   # prepend the modulos2 to the result
		N = int(N/2)            # shift right (integer division by 2)
	}

	# count number of 1s
	r = gsub(/1/,"",r)
	# Return result
	return r
}


# Function to convert a subnetmask (example: 255.255.255.0) to subnet prefix (example: 24)
function subnetmaskToPrefix(subnetmask) {
	split(subnetmask, v, "\\.")
	prefix = count1s(v[1]) + count1s(v[2]) + count1s(v[3]) + count1s(v[4])
	return prefix
}


# 10.11.2.0       0.0.0.0         255.255.255.0   U         0 0          0 eth1
/^(?:[0-9]{1,3}\.){3}[0-9]{1,3}/ {
	destination = $1
	mask = $3
	subnetprefix = subnetmaskToPrefix(mask)
	flags = $4
	gateway = $2
	
	# If its a direct connected network route
	if (gateway == "0.0.0.0") {
		iDirectRoute++
		
		directRoutes[iDirectRoute, "network"] = destination
		directRoutes[iDirectRoute, "mask"] = subnetprefix
	}

	# If its not a directly connected network
	if (gateway != "0.0.0.0") {
		iStaticRoute++
		
		staticRoutes[iStaticRoute, "network"] = destination
		staticRoutes[iStaticRoute, "mask"] = subnetprefix
		staticRoutes[iStaticRoute, "next-hop"] = gateway
	}
}

END {
	writeComplexMetricObjectArrayWithLiveConfig("static-routing-table", null, staticRoutes, "Static routes")
	writeComplexMetricObjectArrayWithLiveConfig("connected-networks-table", null, directRoutes, "Directly Connected Networks")
}

cross_vendor_next_hop_router_inaccessible

package com.indeni.server.rules.library

import com.indeni.ruleengine.InvisibleScopeKey
import com.indeni.ruleengine.expressions.conditions.Equals
import com.indeni.ruleengine.expressions.core._
import com.indeni.ruleengine.expressions.data._
import com.indeni.ruleengine.expressions.scope.ScopeValueExpression
import com.indeni.server.common.data.conditions.True
import com.indeni.server.rules._
import com.indeni.server.rules.library.core.PerDeviceRule
import com.indeni.server.sensor.models.managementprocess.alerts.dto.AlertSeverity


case class NextHopRouterInaccessibleRule() extends PerDeviceRule with RuleHelper {

  override val metadata: RuleMetadata =
    RuleMetadata.builder(
      "cross_vendor_next_hop_router_inaccessible",
      "All Devices: Next hop inaccessible",
      "Indeni will review the routing table and identify when a next hop router is showing as FAILED or INCOMPLETE in the ARP table.",
      AlertSeverity.ERROR,
      Set(RuleCategory.HealthChecks)).build()

  override def expressionTree(context: RuleContext): StatusTreeExpression = {
    StatusTreeExpression(
      // Which objects to pull (normally, devices)
      SelectTagsExpression(context.metaDao, Set(DeviceKey), True),

      // What constitutes an issue
      StatusTreeExpression(
        // The time-series we check the test condition against:
        SelectSnapshotsExpression(context.snapshotsDao, Set("arp-table", "static-routing-table")).multi(),

        // The condition which, if true, we have an issue. Checked against the time-series we've collected
        StatusTreeExpression(

          JoinSnapshotsExpression("arp-table" -> "targetip", "static-routing-table" -> "next-hop")
            .distinct(InvisibleScopeKey("next-hop", "static-routing-table")),

          Equals(
            ScopeValueExpression("success").invisible("arp-table").optional(),
            ConstantExpression(Some("0"))
          )
        ).withSecondaryInfo(
          scopableStringFormatExpression("${scope(\"static-routing-table:next-hop\")}"),
          EMPTY_STRING,
          title = "Inaccessible Next Hops",
          invisibleIdKeys = Set(InvisibleScopeKey("next-hop", "static-routing-table"))
        ).asCondition()
      ).withoutInfo().asCondition()


      // Details of the alert itself
    ).withRootInfo(
      getHeadline(),
      scopableStringFormatExpression("Some of the routes in this device have a next hop which is inaccessible."),
      ConditionalRemediationSteps("Determine why the next hops are not responding.",
        ConditionalRemediationSteps.VENDOR_CP -> "Trying pinging the next hop routers in the list above and resolve any connectivity issues one by one until all pings are successful.",
        ConditionalRemediationSteps.VENDOR_PANOS -> "Log into the device over SSH and review the output of \"show arp\" to identify failures.",
        ConditionalRemediationSteps.OS_NXOS ->
          """|
             |1. Execute the "show spanning-tree" and "show spanning-tree summary"  NX-OS commands to quickly identify the STP root for all the configured vlans.
             |2. Run the "show spanning-tree vlan X detail" NX-OS command to collect more info about the STP topology (X=vlanid).
             |3. Check the event history to find where the Topology Change Notifications originate from by running the next NX-OS command "show spanning-tree internal event-history tree X brief" , (X=vlanid).
             |4. Display the STP events of an interface with the next NX-OS command "show spanning-tree internal event-history tree Y interface X brief" , (X=vlanid, Y=interfaceid).
             |5. Consider to hard code the STP root and backup root to the core switches by configuring a lower STP priority.
             |6. Activate the recommended vPC "peer switch" NX-OS command to a pure peer switch topology in which the devices all belong to the vPC.
             |7. Consider to use Root Guard feature to enforce the root bridge placement in the network. If a received BPDU triggers an STP convergence that makes that designated port become a root port, that port is put into a root-inconsistent (blocked) state.
             |8. For more information please review the following links:
             | <a target="_blank" href="https://www.cisco.com/c/en/us/support/docs/switches/nexus-5000-series-switches/116199-technote-stp-00.html">Spanning Tree Protocol Troubleshooting on a Nexus 5000 Series Switch</a>
             | <a target="_blank" href="https://www.cisco.com/c/dam/en/us/products/collateral/switches/nexus-7000-series-switches/C07-572834-00_STDG_NX-OS_vPC_DG.pdf">Spanning Tree Design Guidelines for Cisco NX-OS Software and Virtual PortChannels</a>
          """.stripMargin,
        ConditionalRemediationSteps.VENDOR_BLUECOAT ->
          """ARP resolve failure to the next hop of the ProxySG.
            |1. Login via SSH to the ProxySG and run the  "show arp-table" command.
            |2. Check for incomplete arp enteries.
            |3. Run the "show interface all" command and check the current status of the network interface with the incomplete arp entery.
            |4. Diagnose the layer 2 connectivity between the ProxySG to the other device.
            |5. If the problem persists, contact Symantec Technical support at https://support.symantec.com for further assistance.""".stripMargin,
        ConditionalRemediationSteps.VENDOR_JUNIPER ->
          """|1. Log into the device over SSH and enter “show arp no-resolve” command to review next-hop MAC and IP address information in ARP table.
             |2. Check for a misconfiguration on interfaces or a physical issue.
             |3. Review the following article on Juniper tech support site: <a target="_blank" href="https://www.juniper.net/documentation/en_US/junos/topics/reference/command-summary/show-arp.html#jd0e289">Operational Commands</a>""".stripMargin
      )
    )
  }
}