Dell Networking OS10 Introduktion til GRE-konfiguration

Summary: Generic Routing Encapsulation (GRE) er en IP-indkapslingsprotokol, der bruges til at etablere en virtuel punkt-til-punkt-forbindelse mellem to routere på tværs af et netværk. Det bruges almindeligvis til tunnelroutingprotokoller som RIP og OSPF mellem forskellige steder. GRE er beskrevet i Request for Comments (RFC 2784. ...

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Instructions

Vigtige emner, der dækkes 

Konfiguration af GRE-tunneler:
  • GRE-tunneler er konfigureret mellem to routere til at sende og modtage GRE-pakker direkte.
  • Konfiguration omfatter opsætning af tunnelgrænseflader, angivelse af tunneltilstand, kilde og destination. 
Begrænsninger og begrænsninger:
  • Der understøttes maksimalt 100 tunneler
  • IPv6 understøttes ikke på underlags- og overlejringsstier.
  • Visse grænseflader og IP-adresser har begrænsninger, når de bruges med GRE-tunneler. 
Tunnel Keepalive-indstillinger:
  • Konfiguration af keepalive-indstillinger til overvågning af tunnelslutpunktets tilgængelighed ved hjælp af ICMP-ekko- og svarpakker (Internet Control Message Protocol). 
ECMP-overlay og underlag (MultiPath) til lige omkostninger:
  • ECMP-belastningsdeling til fordeling af trafik mellem tilgængelige ruter
  • Understøttede kombinationer til overlejrings- og underlægnings-ECMP-ruter. 
Kommandoer og eksempler:
  • Detaljeret kommandosyntaks og eksempler på konfiguration af GRE-tunneler, keepalive-indstillinger og ECMP-ruter 

Mulige problemer med fejlkonfiguration 

Tunnel klapper:
  • Forkerte keepalive-indstillinger kan medføre, at tunnelen ofte går op og ned, hvilket fører til ustabilitet. 
MTU-uoverensstemmelse:
  • GRE-tunneler over stier med forskellige MTU-indstillinger kan forårsage pakkefragmentering eller tab. 
Routing sløjfer:
  • Forkert konfigureret routing kan føre til sløjfer, hvilket forårsager overdreven trafik og potentielle netværksafbrydelser. 

Bedste praksis 

Ensartede MTU-indstillinger:
  • Sørg for, at MTU-indstillingerne er konsistente på tværs af GRE-tunnelen for at undgå fragmentering. 
Korrekt Keepalive-konfiguration:
  • Konfigurer keepalive-indstillinger for at overvåge tunnelens tilstand og undgå unødvendige klapper. 
Klar dokumentation:
  • Oprethold tydelig dokumentation af tunnelkonfigurationer og tilknyttede ruter for at forhindre fejlkonfigurationer. 

Brugsscenarier for GRE-tunneler. 

Tilslutning af eksterne websteder:
  • GRE-tunneler kan forbinde fjerntliggende steder over internettet, hvilket giver mulighed for sikker og effektiv kommunikation. 
Tunneling ikke-IP-trafik:
  • GRE kan indkapsle ikke-IP-trafik, hvilket gør den alsidig til forskellige netværksprotokoller. 
Belastningsjustering:
  • Brug af ECMP med GRE-tunneler kan fordele trafikbelastningen på tværs af flere stier, hvilket forbedrer netværkets ydeevne. 

Eksempel på netværkstopologi 

Forestil dig et netværk med to fjerntliggende steder, websted A og websted B, der er forbundet via internettet. Hvert websted har en router med en GRE-tunnel konfigureret mellem dem. 
 

Topologien ville se sådan ud:

 
Websted A (10.10.10.0/24) ---- OS10-1 ---- Internet ---- OS10-2 ---- Websted B (10.20.10.0/24)

Topologi 

GRE Intro
begrænsning-config

OS10(config)# interface tunnel 10
OS10(conf-if-tunnel-10)# <165>1 2022-11-11T17:55:16.614662+00:00 OS10 dn_alm 731 - - 
 Node.1-Unit.1:PRI [event], Dell (OS10) %IFM_ASTATE_UP: Interface admin state up 
:tunnel10
OS10(conf-if-tunnel-10)# ip vrf forwarding red
% Error: Interface tunnel10, Tunnel mode is mandatory config and must exist for other 
tunnel configs.
OS10(conf-if-tunnel-10)# mode gre-ipv4
OS10(conf-if-tunnel-10)# ip vrf forwarding red
OS10(conf-if-tunnel-10)# ip address 120.1.1.1/24
OS10(conf-if-tunnel-10)# <165>1 2022-11-11T17:55:31.454972+00:00 OS10 dn_alm 731 - - 
 Node.1-Unit.1:PRI [event], Dell (OS10) %IP_ADDRESS_ADD: IP Address add is successful. 
 IP 120.1.1.1/24 in VRF:red added successfully
OS10(conf-if-tunnel-10)# tunnel destination 16.16.16.16
OS10(conf-if-tunnel-10)# tunnel source loopback10
OS10(conf-if-tunnel-10)# <165>1 2022-11-11T17:56:17.197783+00:00 OS10 dn_alm 731 - - 
 Node.1-Unit.1:PRI [event], Dell (OS10) %IFM_OSTATE_UP: Interface operational state is 
up :tunnel10

Behold-konfiguration

OS10(conf-if-tunnel-10)# show configuration
!
interface tunnel10
mode gre-ipv4
no shutdown
ip vrf forwarding red
ip address 120.1.1.1/24
tunnel destination 10.10.10.10
tunnel source loopback10
keepalive down-timer 10
keepalive enable
keepalive probe-interval 6
keepalive up-timer 12

behold-config-1 
GRE tunnel ECMP overlay og underlag 

Underlæg ECMP-ruter Overlejr ECMP-ruter Understøttet
Statisk Statisk Ja
Statisk OSPF Ja 
Statisk BGP Ja
OSPF Statisk Ja
OSPF OSPF Nej
OSPF BGP Ja
BGP Statisk Ja
BGP OSPF Ja
BGP BGP Nej

 

Konfigurer GRE tunnel ECMP-overlejring og -underlag   
OS10(config)# hardware overlay-ecmp-profile mode balanced-overlay-ecmp
OS10(config)# <165>1 2022-10-11T10:25:26.474891+00:00 AG1-9978 dn_alm 717 - - Node.1-
Unit.1:PRI [event], Dell (OS10) %VXLAN_OVERLAY_ECMP_PROFILE_MODIFIED: VxLAN Overlay 
ECMP: Configuration is modified, Save and Reload the device for the profile to be 
effect
Flere ECMP  
OS10# show running-configuration interface tunnel 21
!
interface tunnel21
 mode gre-ipv4
 no shutdown
 ip address 10.10.10.2/24
 tunnel destination 5.5.5.5
 tunnel source loopback3
OS10# show running-configuration interface tunnel 22
!
interface tunnel22
 mode gre-ipv4
 no shutdown
 ip address 10.10.10.3/24
 tunnel destination 6.6.6.6
 tunnel source loopback4
OS10# show running-configuration interface tunnel 23
!
interface tunnel23
 mode gre-ipv4
 no shutdown
 ip address 10.10.10.4/24
 tunnel destination 7.7.7.7
 tunnel source loopback5
OS10# show running-configuration interface tunnel 24
!
interface tunnel24
 mode gre-ipv4
 no shutdown
 ip address 10.10.10.5/24
 tunnel destination 8.8.8.8
 tunnel source loopback6
OS10# show running-configuration route
!
ip route 77.1.1.0/24 100.1.1.2
ip route 77.1.1.0/24 10.10.10.2
ip route 77.1.1.0/24 10.10.10.3
ip route 77.1.1.0/24 10.10.10.4
ip route 77.1.1.0/24 10.10.10.5
OS10# show ip route 10.1.1.0/24
Routing entry for 77.1.1.0/24 
Known via static 
Distance 1, Metric 0
Last update 08:57:53
Routing descriptors Blocks:
 via 100.1.1.2 tunnel10
 via 10.10.10.2 tunnel21
 via 10.10.10.3 tunnel22
 via 10.10.10.4 tunnel23
 via 10.10.10.5 tunnel24
Sådan konfigureres underlagets ECMP  
OS10# show ip route 67.67.67.0/24
Routing entry for 67.67.67.0/24 
Known via ospf, type 
Distance 110,
Metric 21
Last update 09:35:46
Routing descriptors Blocks:
 via 10.1.1.2 ethernet1/1/25:1
 via 12.1.1.2 ethernet1/1/25:2
 via 23.2.2.2 vlan2
 via 23.2.3.2 vlan3
 via 23.2.4.2 vlan4
 via 23.2.5.2 vlan5
 via 23.2.6.2 vlan6
 via 23.2.7.2 vlan7
 via 23.2.8.2 vlan8
 via 23.2.9.2 vlan9
OS10# show ip route 68.68.68.0/24
Routing entry for 68.68.68.0/24 
Known via ospf, type
Distance 110,
Metric 21
Last update 09:36:35
Routing descriptors Blocks:
 via 10.1.1.2 ethernet1/1/25:1
 via 12.1.1.2 ethernet1/1/25:2
 via 23.2.2.2 vlan2
 via 23.2.3.2 vlan3
 via 23.2.4.2 vlan4
 via 23.2.5.2 vlan5
 via 23.2.6.2 vlan6
OS10# show running-configuration interface vlan 2
!
interface vlan2
 no shutdown
 ip address 23.2.2.1/24
 ip ospf 1 area 0.0.0.0
OS10# show running-configuration interface vlan 3
!
interface vlan3
 no shutdown
 ip address 23.2.3.1/24
 ip ospf 1 area 0.0.0.0
OS10# show running-configuration interface vlan 4
!
interface vlan4
 no shutdown
 ip address 23.2.4.1/24
 ip ospf 1 area 0.0.0.0
OS10# show running-configuration interface tunnel 21
!
interface tunnel21
 mode gre-ipv4
 no shutdown
 ip address 131.131.131.1/24
 tunnel destination 67.67.67.67
 tunnel source loopback3
OS10# show running-configuration interface tunnel 22
!
interface tunnel22
 mode gre-ipv4
 no shutdown
 ip address 132.132.132.1/24
 tunnel destination 68.68.68.68
 tunnel source loopback4
GRE-tunnelkommandoer 
  • Eksempel 

OS10# clear counters interface tunnel 10
version 
Interface tunnel 
  • Eksempel

OS10(config)# interface tunnel 10
version.png

IP-adresse

  • Eksempel

OS10(conf-if-tunnel-40)# ip address 10.1.1.1/24
version 
IP-rute 
Kommandotilstand 
  • Eksempel

OS10(conf)# ip route 1.1.1.0/24 interface tunnel 10
OS10(conf)# ip route 2.2.2.0/24 3.3.3.3 interface tunnel 10
version 
IP VRF-videresendelse 
  • Eksempel

OS10(conf-if-tunnel-4)# ip vrf forwarding Vrf_red
version 
Keepalive Down-timer 
  • Eksempel

OS10(conf-if-tunnel-1)# keepalive down-timer 10
version 
keepalive-aktivering 
  • Eksempel

OS10(conf-if-tunnel-1)# keepalive enable
version 
Keepalive sonde-interval  
  • Eksempel

OS10(conf-if-tunnel-1)# keepalive probe-interval 10
version 
Bevar uptimer-kommando 
image.png
  • Eksempel

OS10(conf-if-tunnel-1)# keepalive up-timer 10
version 
Mode tunnel 
  • Eksempel

OS10(conf-if-tunnel-1)# mode gre-ipv4
version 

tunnel destination

  • Eksempel

OS10(conf-if-tunnel-40)# tunnel destination 10.10.10.10
version 
Tunnel source.png
  • Eksempel

OS10(conf-if-tunnel-4)# tunnel source vlan 10
version 
Tunnel TTL 
  • Eksempel

OS10(conf-if-tunnel-1)# tunnel ttl 220
version 
Vis grænsefladetunnel 
  • Eksempel

OS10# show interface tunnel 10
Tunnel 10 is up, line protocol is up
Hardware is Tunnel
Tunnel mode GREv4
Tunnel source IP 2.2.2.2, Tunnel source Intf loopback1
Tunnel destination 7.7.7.7
Tunnel TTL 255
Tunnel keepalive enabled
Keepalive probe interval 10, Up timer 5, Down timer 5
Interface index is 45
Internet address is 10.1.1.1/24
Mode of IPv4 Address Assignment: MANUAL
Interface IPv6 oper status: Enabled
ARP type: ARPA, ARP Timeout: 60
Last clearing of "show interface" counters: 00:11:22
Queuing strategy: fifo
Input statistics:
 0 packets, octets
Output statistics:
 0 packets, octets
Time since last interface status change: 00:27:11
version 
Vis grænsefladen til kørende konfiguration 
  • Eksempel

OS10# show running-configuration interface tunnel 
!
interface tunnel10
 no shutdown
 mode gre-ipv4
 ip address 100.1.1.1/24
 tunnel destination 3.3.3.3
 tunnel source 1.1.1.1
!
interface tunnel20
 no shutdown
 mode gre-ipv4
 ip address 101.1.1.1/24
 tunnel destination 5.5.5.5
 tunnel source 6.6.6.6
OS10# show running-configuration interface tunnel 10
!
interface tunnel10
 no shutdown
 mode gre-ipv4
 ip address 100.1.1.1/24
 tunnel destination 3.3.3.3
 tunnel source 1.1.1.1
version 
Vis tunnel 

Eksempel

OS10# show tunnel
Name 		Mode 	Source-IP 	Destination-IP 	SrcIntf 		TTL 	VRF 	Status 	Protocol
=================================================================================================
Tunnel 1	GREv4 	1.1.1.1 	6.6.6.6 		Loopback 2 		255 	default up 		up
Tunnel 2 	GREv4 	2.2.2.2 	7.7.7.7 		Loopback 123 	255 	default up 		up
Tunnel 3 	GREv4 	3.3.3.3 	8.8.8.8 		Loopback 100 	255 	default up 		up
OS10# show tunnel 10
Name 		Mode 	Source-IP 	Destination-IP 	SrcIntf 		TTL 	VRF 	Status 	Protocol
=================================================================================================
Tunnel 10 	GREv4 	1.1.1.1 	7.6.6.6 		Loopback 2 		255 	default up 		up
version 
Vis IP-grænseflade 
  • Eksempel

OS10# show ip int gig 1/3
GigabitEthernet 1/3 is up, line protocol is down
Internet address is 10.11.0.1/24
Broadcast address is 10.11.0.255
Address determined by user input
IP MTU is 1500 bytes
Helper address is 192.168.0.1
192.168.0.2
Directed broadcast forwarding is disabled
version 
Vis IP-rute 
Vis IP-rute 
  • Eksempel

OS10# show ip route
Codes: C - connected
S - static
B - BGP, IN - internal BGP, EX - external BGP, EV - EVPN BGP
O - OSPF, IA - OSPF inter area, N1 - OSPF NSSA external type 1,
N2 - OSPF NSSA external type 2, E1 - OSPF external type 1,
E2 - OSPF external type 2, * - candidate default,
+ - summary route, > - non-active route
Gateway of last resort is not set
Destination Gateway Dist/Metric Last Change
--------------------------------------------------------------------
C 1.1.1.0/24 via 1.1.1.1 ethernet1/1/1:1 0/0 01:32:53
C 10.1.1.0/24 via 100.1.1.1 loopback1 0/0 00:00:06
C 2.2.2.0/24 via 2.1.1.1.1 Tunnel 1 0/0 00:00:15
OS10# show ip route static
Codes: C - connected
S - static
B - BGP, IN - internal BGP, EX - external BGP, EV - EVPN BGP
O - OSPF, IA - OSPF inter area, N1 - OSPF NSSA external type 1,
N2 - OSPF NSSA external type 2, E1 - OSPF external type 1,
E2 - OSPF external type 2, * - candidate default,
+ - summary route, > - non-active route
Gateway of last resort is not set
Destination Gateway Dist/Metric Last Change
----------------------------------------------------------------------
C 1.1.1.0/24 via 1.1.1.1 ethernet1/1/1:1 0/0 01:32:53
C 10.1.1.0/24 via 100.1.1.1 loopback1 0/0 00:00:06
S 80.1.10.0/24 via 100.1.1.1 tunnel10 1/0 00:02:33
version 
Vis IP OSPF-grænseflade 
OS10# show ip ospf interface tunnel 10
tunnel10 is up, line protocol is up
  Internet Address 100.1.1.1/24, Area 0.0.0.0
  Process ID 1, Router ID 1.1.1.1, Network Type broadcast, Cost: 1
  Transmit Delay is 1 sec, State DR, Priority 1
  Designated Router (ID) 1.1.1.1 (local), Interface address 100.1.1.1
  Backup Designated router (ID) , Interface address 0.0.0.0
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
  Neighbor Count is 0, Adjacent neighbor count is 0
OS10# show ip ospf 1 interface tunnel 10
tunnel10 is up, line protocol is up
  Internet Address 100.1.1.1/24, Area 0.0.0.0
  Process ID 1, Router ID 1.1.1.1, Network Type broadcast, Cost: 1
  Transmit Delay is 1 sec, State DR, Priority 1
  Designated Router (ID) 1.1.1.1 (local), Interface address 100.1.1.1
  Backup Designated router (ID) , Interface address 0.0.0.0
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
  Neighbor Count is 0, Adjacent neighbor count is 0
version 

Vis IP OSPF-statistik 
  • Eksempel

OS10# show ip ospf 1 statistics interface tunnel 10
Interface tunnel10
 Receive Statistics
 rx-invalid 	0 	rx-invalid-bytes 	0
 rx-hello 		0 	rx-hello-bytes 		0
 rx-db-des 		0 	rx-db-des-bytes 	0
 rx-ls-req 		0 	rx-ls-req-bytes 	0
 rx-ls-upd 		0 	rx-ls-upd-bytes 	0
 rx-ls-ack 		0 	rx-ls-ack-bytes 	0
 Transmit Statistics
 tx-failed 		0 	tx-failed-bytes 	0
 tx-hello 		52 	tx-hello-bytes 		3328
 tx-db-des 		0 	tx-db-des-bytes 	0
 tx-ls-req 		0 	tx-ls-req-bytes 	0
 tx-ls-upd 		0 	tx-ls-upd-bytes 	0
 tx-ls-ack 		0 	tx-ls-ack-bytes 	0
 Error packets (Receive statistics)
 bad-src 		0 	dupe-id 			0 	hello-err	 0
 mtu-mismatch 	0 	nbr-ignored 		0 	wrong-proto  0
 resource-err 	0 	bad-lsa-len 		0 	lsa-bad-type 0
 lsa-bad-len 	0 	lsa-bad-cksum 		0 	auth-fail    0
 netmask-mismatch 0 hello-tmr-mismatch 	0 	dead-ivlmismatch 0
 options-mismatch 0 nbr-admin-down 		0 	own-hellodrop    0
 self-orig 		0 	wrong-length 		0 	checksumerror 	 0
 version-mismatch 0 area-mismatch 		0
version 
 
 

Additional Information

Affected Products

SmartFabric OS10 Software
Article Properties
Article Number: 000228691
Article Type: How To
Last Modified: 03 Oct 2025
Version:  2
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