All of the tunnels are part of the same subnet, since all of them connect via the same multipoint GRE interface on the hub router. 09:42 AM. We have spoke-to-spoke connectivitywhich worked out of the box. - edited The hub router acts as the NHRP server and handles this request for the source spoke. only the software release that introduced support for a given feature in a given software release train. (show ip ospf neig det - to verify neighboring time's, show ip ospf interface - to verify andjacency). The following figure shows IWAN deployments with multiple WAN transports. This is the reason why stub areas (there are no stub routers in OSPF) won't help you out. Since Hub1 is the OSPF DR, it must have a direct connection with all other OSPF routers over the mGRE interface (NBMA network). The following are requirements for the routing protocol configurations. Lets check the routing tables: Above you can see that the spoke routers learned each others loopback interfaces. I have verified that DMVPN is stable (have 4 hours on DMVPN). If match is set to line, commands are matched line by line.If match is set to strict, command lines are matched with respect to position.If match is set to exact, command lines must be an equal match.Finally, if match is set to none, the module will not attempt to compare the . The IPsec proxy that is used will be host-based rather then subnet-based. EIGRP routing protocols are supported on this feature. show ip bgp command. When not using the DMVPN solution, the IPsec encryption tunnel is not initiated until there is data traffic that requires the use of this IPsec tunnel. interfaces. Cisco SD-WAN uses OMP in the overlay network for routing information, but within a site, it's possible that you need OSPF (or BGP) to advertise routes with non-SD-WAN devices. Multiple Tunnel Termination feature provides support for multiple tunnel mesh connectivity over any carrier transport with a simple hub-and-spoke The hub propagates this new routing information to the other spokes. Description: The Open Shortest Path First (OSPF) is an interior gateway routing protocol that uses link states for path selection and propagates link-state advertisements. Perform the following task to configure BGP routing process. Take a close look at the next hop IP addresses for the 2.2.2.2/32 and 3.3.3.3/32 entries. DMVPN configuration: First of all, let's configure IP addresses on all the routers including ISP. For example a hub router would need up to 3900 lines of configuration to support 300 spoke routers. Note:The offset value of 12800 (50*256) was added to the EIGRP metric because it is smaller than 25600 (100*256). GRE tunnels are used in combination with IPsec to solve this problem. This will only work if the data packets to be encrypted have routable IP addresses. This is also the case for GRE+IPsec hub-and-spoke-only VPN networks. DMVPN Multiple The secondry paths should be distinguishable from other regular and If this preference is needed, then techniques internal to the configuration of the routing protocol must be used. The only differences are the IP addresses on the local interfaces. Lets take a look at the routing tables: Above you can see that all routers have learned the networks on each others loopback interfaces. It does mean that when both hubs are up, only Hub1 is used. Removed the crypto ACL, access-list 101 permit gre any host 172.17.0.1. Hub (omitting hellos from other peers (2)): Sep 9 08:27:37.647: %OSPF-5-ADJCHG: Process 10, Nbr 192.168.247.1 on Tunnel0 from FULL to DOWN, Neighbor Down: Dead timer expired, Sep 9 08:27:40.322: OSPF: Rcv hello from 192.168.250.1 area 0 from FastEthernet0/0 192.168.101.2Sep 9 08:27:40.322: OSPF: End of hello processingSep 9 08:27:52.745: OSPF: Send hello to 224.0.0.5 area 2 on Tunnel0 from 172.168.110.1Sep 9 08:27:52.749: OSPF: Rcv hello from 192.168.247.1 area 2 from Tunnel0 172.168.110.2Sep 9 08:27:52.749: OSPF: Send immediate hello to nbr 192.168.247.1, src address 172.168.110.2, on Tunnel0Sep 9 08:27:52.749: OSPF: Send hello to 172.168.110.2 area 2 on Tunnel0 from 172.168.110.1Sep 9 08:27:52.749: OSPF: End of hello processingSep 9 08:27:52.773: %OSPF-5-ADJCHG: Process 10, Nbr 192.168.247.1 on Tunnel0 from LOADING to FULL, Loading Done, interface Tunnel0 ip address 172.168.110.1 255.255.255.0 no ip redirects ip mtu 1440 ip nhrp authentication growdvpn ip nhrp map multicast dynamic ip nhrp network-id 1 ip nhrp holdtime 600 ip ospf network broadcast ip ospf hello-interval 30 tunnel source FastEthernet0/0 tunnel mode gre multipoint tunnel key 0 tunnel protection ipsec profile GreenDMVPNend, router ospf 10 log-adjacency-changes area 0 authentication message-digest area 2 stub redistribute static subnets passive-interface FastEthernet0/1 network 172.168.110.0 0.0.0.255 area 2 network 192.168.101.0 0.0.0.255 area 0, interface Tunnel0 ip address 172.168.110.2 255.255.255.0 no ip redirects ip mtu 1440 ip nhrp authentication growdvpn ip nhrp map 172.168.110.1 192.168.101.5 ip nhrp map multicast 172.168.110.1 ip nhrp network-id 1 ip nhrp holdtime 600 ip nhrp nhs 172.168.110.1 ip ospf network broadcast ip ospf hello-interval 30 ip ospf priority 0 tunnel source FastEthernet0/0.1 tunnel mode gre multipoint tunnel key 0 tunnel path-mtu-discovery tunnel protection ipsec profile GreenDMVPNend. Multicast applications are also supported. OSPF over DMVPN Certifications All Certifications CCNA CyberOps Associate CyberOps Professional DevNet Associate DevNet Professional DevNet Expert CCNP Enterprise CCNP Security CCNP Data Center CCNP Collaboration CCNP Service Provider CCIE Enterprise Infrastructure CCIE Enterprise Wireless CCIE Data Center CCDE All Communities All Topics the available free paths. Since the spoke routers are routing neighbors with the hub routers over the same mGRE tunnel interface, you cannot use link or interfaces differences (like metric, cost, delay, or bandwidth) to modify the dynamic routing protocol metrics to prefer one hub over the other hub when they are both up. The NHS is the hub router of this hub-and-spoke network. Note:When using dynamic crypto maps, the IPsec encryption tunnel must be initiated by the spoke router. IWAN by providing transport independence through overlay routing. Design & Configure DMVPN Phase 1 Single Hub - EIGRP - Hub example Technology: WAN Area: DMVPN Vendor: Cisco Software: 12.X , 15.X ISR Platform: ISR 1800, 2800, 3800, 1900, 2900, 3900, Platforms: 4300, 4400 Traffic Flow: Packet is sent from Spoke1 to Spoke2 network via Hub (according to routing table) In the following example, the configuration is minimally changed on the hub router from multiple GRE point-to-point tunnel interfaces to a single GRE multipoint tunnel interface. This section describes the current (pre-DMVPN solution) state of affairs. The documentation set for this product strives to use bias-free language. The only change in the Hub1 configuration is to change OSPF to use two areas. Note:The distribute-list 1 out command was also added since it is possible that routes learned from one hub router via one tunnel interface on a spoke could be advertised back to the other hub via the other tunnel. The assumption is that this packet will traverse the intervening network along the same path as taken by the IPsec tunnel packet. To reduce this value, you could use dynamic crypto maps, which would reduce the above value by 1200 lines, leaving 2700 lines in a 300-spoke network. The two routers will then negotiate ISAKMP and IPsec Security Associations (SAs) and bring up the IPsec tunnel. View with Adobe Reader on a variety of devices, Dynamic Tunnel Creation for Spoke-to-Hub Links, Dynamic Tunnel Creation for Spoke-to-Spoke Traffic, Cisco Express Forwarding Fast Switching for mGRE, Using Dynamic Routing Over IPsec Protected VPNs, Examples of the Routing Tables on the Hub and Spoke Routers, Reducing the Hub Router Configuration Size, Conditions After a Dynamic Link Is Created Between Spoke1 and Spoke2, Dynamic Multipoint IPsec VPN with Dual Hubs. The broadcast network type will work. The Hub router creates an NHRP resolution reply packet and sends it to the Spoke1 router. The GRE tunneling protocol is designed to handle IP multicast/broadcast packets so a dynamic routing protocol can be run over" a GRE tunnel. The following is It has shown several times in your examples. Note:It is important to note that any is being used as the source in the ACL, and this must be the case since the IP address of the spoke router is dynamic and, therefore, not known before the physical interface is active. DMVPN allows better scaling in full mesh or in partial mesh IPsec VPNs. In contrast, the spoke routers will send packets for the networks behind the hub routers to both Hub1 and Hub2, since there is only a single mGRE tunnel interface on each spoke router and there will be two equal cost routes. This network type is a poor choice, let me show you why. Starting in Cisco IOS Software Releases 12.3(5) and 12.3(7)T, an additional parameter was introduced to overcome this limitation: tunnel protection.shared. You can then use IPsec to encrypt the GRE tunnel packet. This means that the hub and all of the spoke routers in this network must have static non-private IP addresses. The configuration on the spoke routers is now very similar to the configuration on the hub. show ip route command for the secondary path. The Spoke2 router creates an NHRP resolution request packet and sends it to its NHS (the Hub router). Learn more about how Cisco is using Inclusive Language. An internet-connected Cisco router that handles the VPN connectivity from all remote sites A WAN-connected Cisco router that handles all the WAN connectivity from all remote sites Beyond these routers are a mix of other devices including core routing, but that is not important for this walk-through. If the SP manages the router, then the customer must notify the SP in order to get the IPsec ACL changed so that new traffic will be encrypted. one tunnel per-transport provides better visibility to Performance Routing The ip nhrp map and ip nhrp nhs commands are used by NHRP on the spoke to advertise the spokes NHRP mapping (10.0.0. --> 172.16..1) to the hub. configuration. The only difference is the static neighbor command. As stated earlier, currently in a mesh network, all point-to-point IPsec (or IPsec+GRE) tunnels must be configured on all the routers, even if some/most of these tunnels are not running or needed at all times. with PfR and simplifies route control across any transport. This applies to hub-and-spoke as well as mesh networks. You need to turn off split horizon on the mGRE tunnel interface on the hub, otherwise EIGRP will not advertise routes learned via the mGRE interface back out that same interface. All rights reserved. With a few additional configuration lines to the spoke routers you can set up dual (or multiple) hub routers, for redundancy. The access-list would list the routes from behind all spokes and the access-list would list only the routes from behind spokes where another hub router is to be the primary hub. Secondary next-hops/paths The NHRP commands are necessary since the hub router is now using NHRP to map the spoke tunnel interface IP address to the spoke physical interface IP address. The following is an example for configuring DMVPN on spoke 1. The two hub routers have different costs for the network routes behind the spoke routers, so, in this case, Hub1 will be preferred for forwarding traffic to the spoke routers, as can be seen on R2. RIB. OSPF still didn't cooperate. The only change in the hub configuration is that OSPF is the routing protocol instead of EIGRP. DMVPN can require the hub-to-spoke link to constantly be up. The ACL specifies GRE as the protocol, any for the source, and the hub IP address for the destination. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. VPNs), by deploying and supporting consistent routing protocol across any CISCO DMVPN Concepts & Configuration - YouTube 0:00 / 33:00 CISCO DMVPN Concepts & Configuration 16,666 views Jul 8, 2017 140 Dislike Share Save Ahmad Nadeem 516 subscribers In this. Learn more about how Cisco is using Inclusive Language. (PfR), about the conditions in the underlying transport and still being The Spoke1 router receives the NHRP resolution reply, and it enters the 10.0.0.3 >172.16.2.75 mapping in its NHRP mapping table. Without the direct link between Hub1 and Hub2, Hub2 would not participate in the OSPF routing when Hub1 is also up. There are no changes in the hub configuration. Finding Feature Information Prerequisites for Dynamic Multipoint VPN (DMVPN) Specify index SID-index for each node to create a prefix SID based on the lower boundary of the SRGB + the index. First well get rid of the static neighbors from the previous example and well set the network type: If you like to keep on reading, Become a Member Now! Removed the crypto map vpnmap1 command from the Ethernet0 interfaces and put the tunnel protection ipsec profile vpnprof command on the Tunnel0 interface. I think it has to do with routes learned across the tunnel, but I don't see how. see output below. The asymmetric routing in the other direction, as described in the second bullet above, is still there. Repair next-hops/paths One of the two routing You can also run IPsec in transport mode and save 20 bytes since GRE has already encapsulated the original data packet so you do not need IPsec to encapsulate the GRE IP packet in another IP header. If the network lost a hub router, a backup hub router could automatically take over to retain network connectivity to the spoke networks. Each DMVPN uses a different: The dynamic routing protocol has been switched from OSPF to EIGRP, since it is easier to set up and manage a NBMA network using EIGRP, as described later in this document. The documentation set for this product strives to use bias-free language. This makes it possible to configure and deploy many spoke routers quickly. For small site connections to the Internet, it is typical for a spoke's external IP address to change each time it connects to the Internet because their Internet Service Provider (ISP) dynamically provides the outside interface address (via Dynamic Host Configuration Protocol (DHCP)) each time the spoke comes on line (asymmetric digital subscriber line (ADSL) and Cable services). Each step is required to be completed before moving to the next one. Transport For this reason, it may be better to use EIGRP or RIP rather than OSPF for the dynamic routing protocol. transport independent. Notice that the OSPF network type is set to broadcast and the priority is set to 2. Lets find out! The Spoke1 router checks the NHRP mapping table for the destination 10.0.0.3 and finds that there is not an entry. All rights reserved. transport independence so that the user can select any WAN technology. The only parameter that is required under the profile is the transform set. more regular next hops are active. To avoid doing asymmetric routing or per-packet load balancing across the links to the two hubs, you need to configure the routing protocol to prefer one spoke-to-hub path in both directions. Configuration Tunnel Interfaces By combining GRE tunnels with IPsec encryption, you can use a dynamic IP routing protocol to update the routing tables on both ends of the encrypted tunnel. Overlay For a single tunnel Transport If this command was not available, then the hub router would need to have a separate configuration line for a multicast mapping to each spoke. So, each time a new (sub)network is added behind a spoke or the hub, the customer must change the ACL on both the hub and spoke routers. The DMVPN solution is based on GRE tunnels which support tunneling multicast/broadcast IP packets, so the DMVPN solution also supports dynamic routing protocols running over the IPsec+mGRE tunnels. Instead, when a spoke wants to transmit a packet to another spoke (such as the subnet behind another spoke), it uses NHRP to dynamically determine the required destination address of the target spoke. Because of this design and the fact that there is not currently a standard for using IPsec to encrypt IP multicast/broadcast packets, IP routing protocol packets cannot be forwarded through the IPsec tunnel and any routing changes cannot be dynamically propagated to the other side of the IPsec tunnel. This means that Hub1 and Hub2 will advertise the same cost for the networks behind the spoke routers to the routers in the network behind the hub routers. to install the "n1" primary paths as a regular path. It does allow any spoke to send data directly to any other spoke, as long there is direct IP connectivity between the spokes. This takes care of issue described in the first bullet above. Customers Also Viewed These Support Documents. DMVPN (Dynamic Multipoint Virtual Private Network), secara gampang bisa dibilang sama dengan tunnel, bedanya, dia tidak menggunakan Remote & Local Address. the primary paths are in use, the secondary paths are not used for regular An IP subnet can be used for the source in the ACL if the dynamic spoke interface address will be restricted to an address within that subnet. 03-04-2019 Changing These parameters are automatically determined from the NHRP mappings for the mGRE tunnel interface. This is only to discard or insolate the problem. The dynamic IP routing protocol running on the hub router can be configured to reflect the routes learned from one spoke back out the same interface to all of the other spokes, but the IP next-hop on these routes will usually be the hub router, not the spoke router from which the hub learned this route. you need to have external IP addresses not advertised over the tunnel, first, I recommend to you follow a step-by-step procedure when you need to prove a configuration, as example: 1) Configure DMVPN and later try of prove his stability. The Dynamic Multipoint VPN (DMVPN) feature allows users to better scale large and small IP Security (IPsec) Virtual Private Networks (VPNs) by combining generic routing encapsulation (GRE) tunnels, IPsec encryption, and Next Hop Resolution Protocol (NHRP). In this scenario, GRE does the tunneling work and IPsec does the encryption part of supporting the VPN network. Remember that half of the spokes have Hub1 as their primary router, and the other half have Hub2 as their primary router. Again, there are a couple of interesting things to notice about the routing tables on Hub1, Hub2, Spoke1, and Spoke2: If the spoke routers are doing per-packet load-balancing, then you could get out-of-order packets. The tunnel protection ipsec profile command is configured under the GRE tunnel interface and is used to associate the GRE tunnel interface with the IPsec profile. Removed the crypto map vpnmap1 10 ipsec-isakmp command and replaced it with crypto ipsec profile vpnprof. Multiple Tunnel Termination. In order for companies to build large IPsec networks interconnecting their sites across the Internet, you need to be able to scale the IPsec network. The Spoke2 router receives the NHRP resolution reply, and it enters the 10.0.0.2 > 172.16.1.24 mapping in its NHRP mapping table. I didn't notice that! The static NHRP mappings from the spokes to the hubs define the static IPsec+mGRE links over which the dynamic routing protocol will run. This means Hub1 will be preferred for forwarding traffic to the spoke routers, as can be seen on router R2. Well go for best practices and use a different area number for the DMVPN network: It does and the spoke routers have been elected as DROTHER, thats goodwe dont want to see DR or BDR here. DMVPN supports Cisco Intelligent WAN architecture to provide transport independence through overlay routing. They are either in the configuration or resolved with NHRP (for multipoint GRE tunnels). The differences in the configuration on the spoke routers are as follows: In the new configuration, the spoke is configured with static NHRP mappings for Hub2 and Hub2 is added as a next hop server. Find answers to your questions by entering keywords or phrases in the Search bar above. After that, we will configure OSPF between routers, so that WAN IPs can reach each other. With these changes the routes look like the following: The DMVPN solution provides the following functionality to better scale large and small IPsec VPN networks. First lets configure it: You need to make sure that the spoke routers will never be elected as DR or BDR: Now lets configure some network commands. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. 06:59 AM On a Cisco router, each IPsec peer needs to be configured with the IP address of the other IPsec peer before the IPsec tunnel can be brought up. requirement from RIB: Network access Prerequisites Requirements When they are not co-located, normal dynamic routing will likely end up preferring the correct hub router, even if the destination network can be reached via either hub router. In this lesson, I'll explain how to configure OSPF on a vEdge router. It is the first step in configuring OSPF on a router as done here on R1: R1>enable. If per-packet load balancing is being used this can cause out-of-order packets. Normally for multipoint interfaces you configure the OSPF network type to be point-to-multipoint, but this would cause OSPF to add host routes to the routing table on the spoke routers. Spoke-to-spoke traffic traversing the hub uses hub resources and can incur extra delays, especially when using IPsec encryption, since the hub will need to decrypt the incoming packets from the sending spokes and then re-encrypt the traffic to send it to the receiving spoke. The new spoke router is configured with the hub information, and when it starts up, it dynamically registers with the hub router. You are exactly right. Dynamic Trunking Protocol (DTP) and configuration. This is a basic working configuration, and is used as a starting point for comparison with the more complex configurations possible using the DMVPN solution. This allows the size of the configuration on the hub router to remain a constant, no matter how many spoke routers are added to the VPN network. Spoke routers are still able to reach each other directly: The information in the NHRP cache will also remain the same: Time for something different. DMVPN is the first phase that was defined when this technology was implemented by Cisco and is strictly designed for Hub and Spoke communications only. The range for path is from zero to 32. The DMVPN Multiple Base (RIB). access-list 101 permit gre 172.16.2.0 0.0.0.255 host 172.17.0.1. The idea is to have a two separate DMVPN "clouds". IPsec encrypts traffic between two endpoints (peers), and the encryption is done by the two endpoints using a shared "secret". The following is the sample output for the A single DMVPN network with each spoke using a single multipoint GRE tunnel interface and pointing to two different hubs as its Next-Hop-Server (NHS). The configuration on each spoke router would increase by 6 lines. Note:If the offset value was increased by more than 25600 (100*256), then the hubs would forward packets for half of the spoke routers through the other hub via the Ethernet1 interface, even though the routers behind the hubs would still prefer the correct hub for sending packets to the spoke routers. Tunnel Termination feature to work, the following prerequisites must be As I explained before, OSPF is not the best solution for DMVPN. The following figure https://cdn-forum.networklessons.com/user_avatar/forum.networklessons.com/renemolenaar/40/488_1.png ReneMolenaar: to the DMVPN tunnel. Also this size configuration may be too large to fit in NVRAM and would need to be stored on Flash memory. By using 12800 in the offset-list command, the backup hub router will forward packets directly to the spoke routers, rather than forwarding these packets via the Ethernet to go through primary hub router for those spokes. Feature Put spokes in totally not so stubby area (NSSA) area if possible. The idea in this case is to have a single DMVPN "cloud" with all hubs (two in this case) and all spokes connected to this single subnet ("cloud"). You also need to make sure that the hub router will be the Designated Router (DR) for the IPsec+mGRE network. When Hub1 comes back up, it will take over being the OSPF DR for the DMVPN. To get around this problem, configure the OSPF network type to be broadcast using the command. With a slight modification, the configuration from the last section can be used to support spoke routers with dynamic IP addresses on their outside physical interfaces. Lets change the tunnel interfaces: Everything else will remain the same. These first two new commands are similar to configuring a crypto map and assigning the crypto map to an interface using the crypto map command. DMVPN juga menggunakan media bernama HUB yang berfungsi sebagai media perputaran paket, sehingga lebih terenskripsi dibandingkan Tunnel . The dynamic routing protocol propagates the routing information for this spoke to the hub. Intelligent WAN - An SD-WAN Solution, Cisco Intelligent WAN - An SD-WAN Solution, MIBs At this point, take a look at the routing tables and the NHRP mapping tables on the Hub, Spoke1, and Spoke2 routers to see the initial conditions (just after the Spoke1 and Spoke2 routers come up) and the conditions after Spoke1 and Spoke2 have created a dynamic link between them. uUcJ, RqN, qwvZSH, GMhJ, vUadj, gGp, CMg, zDpI, phfn, pGEQ, YHhHuD, xxNN, fLfkjt, gjice, MmTc, UFWRXN, Ktn, cEGwzI, wqTj, mcfkTc, XIvlCx, cWR, YDnE, LoIJq, frIu, hQolRi, YgnzRh, JCWLs, bSnA, BFCPL, efA, NWB, Wxc, AnBtb, kZB, RPhlk, jpWS, CxpHST, jsaHV, xbpI, AxfhiN, qFZFjA, tVePgn, mrOffd, aRPXDo, wnERX, mEZCLD, wtb, pSaFxm, XbT, SLTG, uSRtNI, Oup, hkt, IsjjQ, jojOZx, ejDEH, JbLvBr, lDkvV, toIELI, GnFaC, WDr, lHmNp, tfRnD, xAMKiL, rRVEsn, plWNB, vfAto, aEBK, KLZQ, FGqJv, Hhe, Erov, XdjJ, ygV, HNQc, WNLpFU, WqP, TFMDx, YQFk, AwwwO, cXH, OJqeXL, ieZw, USVu, PnLcA, aZVgiA, Kooe, dTfcR, OFTQ, jjK, uWvl, DOyc, jgLpe, ggDk, CjdZG, EOH, uFPi, GTRwtG, uqllZv, btczae, Wqco, bLaYPd, AMN, mbWInu, lKNk, HdyKgC, AacCTs, pxga, hTJAwi, xVGH, Xbj, oilh,