I notice there is no snmp server group command but i can specify a group after when adding a user. Ccnp tshoot chapter 5 exam answers version 7 score 100%. Remote rmm 1400 version 5 configuration guide command line. I read that nxos has ifindex persistence enabled by default. I know they refer to our vlans on the nexus and i am currently monitoring those.
Select v1, v2, or v3 from the snmp version dropdown list and then configure. Cisco nexus 5000 series troubleshooting guide free ebook download as pdf file. As an aside, some systems seem to be able to have ifindex persistence enabled, like some cisco equipment. May 07, 2019 the simple network management protocol snmp is an applicationlayer protocol that provides a message format for communication between snmp managers and agents.
Cisco nxos based devices contain a buffer overflow vulnerability in the simple network management protocol snmp subsystem. Ive been looking at migrating some customers catalyst 4500 and catalyst 6500 switches to nexus 7000 switches. Please use port 2055 initially as this is the preset netflow auditor port. This action applies only to interfaces that have ifdescr and ifindex entries in the ifindex table of the ifmib. We are using opmanager to montior interface devices on remote linux boxes. Ifindex is a unique identifying number associated with a physical or logical interface. Loopback0 can be changed to another interface such as fastethernet00 but it is good practice to choose an interface that will consistently have the same ip address. Also, im not sure if that command would actually work on the vpn interfaces, or if it would only apply to physical and vlan interfaces. The snmp interface index for each interface will stay the same, even if the device is rebooted.
Nxos also uses hsrp as keyword, while ios uses standby. You will want to add snmp server ifindex persist to your config so these values dont change after a. Understanding snmp 271 snmp versions 272 snmp manager functions 273 snmp agent functions 274 snmp community strings 274 using snmp to access mib variables 274 snmp notifications 275 snmp ifindex mib object values 275. To determine your current settings, run the following command on your router or switch. Managing 15000 network devices with ansible computer. How can i configure an oid on 7200 cisco community. Alarm traps are sent to all enabled snmp management hosts. Although relevant rfcs do not require that the correspondence between particular ifindex values and their. Earlier nxos releases have incorrect packetspersecond and bitspersecond statistics. Monitor ipsec tunnel traffic on cisco asa solutions. View and download cisco 4500m command reference manual online. In this circumstance you must ensure snmp server ifindex persist is used. Snmp ifindex nxos hi robert, you can use show interface snmp ifindex.
Snmp configuration guide, cisco ios xe release 3se cisco. But surely, if you want to know which interface is which, you can just inspect the ifdescr field instead. Both commands snmp server ifindex persist and snmp ifmib ifindex persist are supported on the cisco 7606s core router from a configuration point of view. Under which circumstances snmp interface indexifindex in. To use the dhcp relay, dhcp services also has to be enabled. If snmp server ifindex persist is not used, then it is possible that ifindexes are mapped differently than before. These products are affected by one or more of the following vulnerabilities.
This is an older version of my command summary, the updated version is available at migrating to nexus 7000 from catalyst 6500 and 4500 switches as of nxos 6. Nfa uses flow information netflow and sflow instead of snmp to analyze the communication. Virtualization support for snmp cisco nxos supports one instance of the snmp per virtual device context vdc. This does not work on ios xe or nxos devices, including asrs and nexus 7k or 3ks. User roles contain rules that define the operations allowed for a particular user assigned to a role. Issue is seen when the config is huge multiple interfacesindexes and snmp server ifindex persist config present related community discussions unable to. Nxos uses cidr notation for ip addresses, but can accept the ipaddress maskformat as well. You can configure cisco nxos to send notifications to multiple host receivers. If you want to dump all of the snmp oids from a discovered device in scom 2012, you can click the network device and run the task for an snmp walk. Under which circumstances snmp ifindex in cisco ios might change. When they came up they reindexed the interfaces table and now we have incorrect data in all of our interface sensors. I found an ios command snmp server ifindex persist that appears to do just that, but it doesnt seem to be supported on the asa. Cisco nxos generates snmp notifications as either traps or informs.
Cisco nxos software snmp packet denial of service vulnerability. Snmp provides a standardized framework and a common language used for the monitoring and management of devices in a network. Ifindex the problem is, when i send the reset counters interface command, snmpget still return the number of errors whereas a display interface x on the switch shows nothing. Migrating to nexus 7000 from catalyst 6500 and 4500. Cisco nexus, cisco unified computing system ucs, cisco mds 9000 series multilayer switches, and cisco series connected grid routers cgr are all based on the cisco nxos operating system. The value for each interface sublayer must remain constant at least from one reinitialization of the.
The snmp server ifindex persist global configuration command enables and disables ifindex persistence for all interfaces on the routing device. To ensure consistency of interface reporting, enable snmp ifindex persistence on devices sending netflow to the discover appliance. Managing 15000 network devices with ansible free download as pdf file. Given the partial netflow configuration, which command sequence is required to forward the traffic statistics of interfaces fa00 and fa01 to the netflow traffic collector. However, operation wise, the card index is not persistent, i. Technical cisco content is now found at cisco community, and cisco devnet. Configure netflow cisco commands quick start summary. Minion configuration parameters when nodes are configured with a nondefault location, the associated service monitors are executed on a minion configured with that same location. If cisco nxos never receives a response, it can send the inform request again. I decided to refresh my earlier article on migrating to nexus 7000 from catalyst 6500 and 4500 switches with some 5.
Cisco 7600 series router software configuration guide, cisco. Cisco nxos software snmp buffer overflow vulnerability. In other words, the ifindex numbering of the interfaces is only guaranteed to persist until the machine is rebooted. If you select this option, the snmp credentials are applied based on the shared snmp credentials settings. A vulnerability in the simple network management protocol snmp module of cisco nxos software could allow an unauthenticated, remote attacker to access sensitive information. If you are using nxos v5, you must have a minimum version of nxos v5. Supervisor engine 6 does not support supervisor engine 5 for this setup of the device you can use a regular netflow configuration such as.
Is there an easy fix for interface table reindex problem. For most software, the ifindex is the name of the interface. Cisco nxos software snmp information disclosure vulnerability. Cisco me 3400 ethernet access switch software configuration guide. Cisco 7600 series router software configuration guide, cisco ios release 15s. Set up snmp credentials for authentication and encryption. Snmp the central alarm table supports snmp through alarm traps in the aimediationv2. If necessary, change the settings of particular interfaces with the ifindex persist command. Nxos aireos arista eos switching, routing aruba wireless f5 bigip load balancing fortinet fortimanager firewall 2 configuration management that map to specific tasks for network operations.
These boxes have vlans that we use to collect information about. An attacker could exploit this vulnerability by making a large number of requests to the listening snmp. Although relevant rfcs do not require that the correspondence between particular ifindex values and their interfaces be. Here are some redirects to popular content migrated from docwiki. An snmp manager that receives an inform request acknowledges the message with an snmp response protocol data unit pdu. Such interfaces will appear multiple times in ifmib. Oct 26, 2005 one of the most commonly used identifiers in snmp based network management applications is the interface index ifindex value. A trap is an asynchronous, unacknowledged message sent from the agent to the snmp managers listed in the host receiver table. Configure netflow cisco netflow commands explained. Nxos system management configuration guide, release 6. Snmp can check the communication traffic passing through interfaces such as switches and routers. Cisco 7600 series router software configuration guide.
Necessary or not, this reporting in option template is more standard. May 24, 2011 nxos uses a different concept for the same purpose, known as user roles. An authenticated, remote attacker who can submit a malicious snmp query via udp port 161 could exploit the vulnerability to trigger a buffer overflow condition in the snmp component of the device. The problem is, once you open up the txt file and look through it, all of the strings are in hex. The cisco docwiki platform was retired on january 25, 2019. However, snmp cannot be easily used to check the details of the communication traffic. Nxos aireos arista eos switching, routing aruba wireless f5 bigip load balancing fortinet fortimanager firewall configuration management that map to specific tasks for network operations. In junos, as far as i know, something like this should be built in by design as there is a file vardbdcd. As var is mounted to devadx, it should survive reboot. I know this has come up in the past and always gets answered with snmp server ifindex persist. Cisco nexus 5000 series troubleshooting guide command line. I notice there is no snmpserver group command but i can specify a group after when adding a user. If you are using a cisco nexus 5000 series, you cannot export netflow from the device to a flow gateway for the purposes of forwarding that data to a netprofiler.
Cisco nxos cannot determine if the trap was received. Multiple vulnerabilities in cisco nxosbased products. F16371 usrn540 rs232 to ethernet rs485 to rj45 rs422 to tcp. Snmp configuration guide, cisco ios xe release 3se cisco wlc 5700 series chapter title. But i also happened to read about a possible cisco bug on the nexus which causes the ifindex can change. What is the effect of the snmp server ifindex persist command. Snmp is widely used to check the communication status of the network. Old 3750 has a fixed schema so that you know in advance every ifindex value for every stack member mib object for example ifindex of the fa101 interface is always 1, ifindex of the fa201 interface is always 10501, ifindex value of the portchannel 1 is always 5001 and so on.
In case the monitor is using the snmp protocol the default configuration for timeout and retry are used from the snmp configuration snmp config. In order to receive alarm traps, at least one snmp management host must be configured. Cisco nexus 9000 series configuration manual pdf download. Netflow config on cisco ios, iosxe, nxos thatcyberguy. Hp 5500, ifinerror counter and snmp giving me troubles. Ive also added some additional commands that i felt may be useful, such as the bgp commands. Detta kommando hette tidigare snmp server ifindex persist. A unique value, greater than zero, for each interface. Snmpv3 user configuration with nso cisco community. Im getting data, inbound errors on interfaces, through snmp, on a hp 5500.
However, still sometimes ifindex values are changed. For more information on how to enable snmp ifindex persistence on your network devices, refer the configuration guide provided by the device manufacturer. Cisco nexus 7000 series nxos system management configuration. Ps script to convert snmp walk strings in scom 2012 to human. In nxos, the hsrp feature needs to be enabled before it can be used.
The vulnerability is due to a failure to respond to invalid requests in the same manner when specifying a vlan id. Hi, i have a network monitoring tool that fails after my fw restart because the snmp mib ifindex changes everytime it reboots. Migrating to nexus 7000 from catalyst 6500 and 4500 switches. One of the most commonly used identifiers in snmp based network management applications is the interface index ifindex value. It is recommended that values are assigned contiguously starting from 1. I recently added netflow to our nexus 7k and getting these messages. Im a bit confused on the differences between the two oss. Cisco ios commands cisco ios master commands list, release 12. Digitoll netflow collection engine will automatically discover the devices on receipt of the netflow. They have had a command for a number of years to fix this behavior. Networkadmincomplete readandwrite access to the entire nxos device only available in the default vdc. Multiple cisco discovery protocol vulnerabilities in cisco nxos based products cisco nxos software snmp and license. Cisco nexus 5000 series nxos software configuration guide.