This document provides an overview and guidance on IBM Cloud's Direct Link services. It describes the different types of Direct Link connections available, including Direct Link Exchange, Direct Link Connect, and Direct Link Dedicated. Details are provided on ordering processes, network configurations, and BGP routing considerations for establishing private connectivity between a customer's on-premise network and IBM Cloud infrastructure. Redundant link configurations using multiple Direct Link orders are also discussed.

1. © 2019 IBM Corporation
IBM Cloud
Direct Link Guide
2019/7/19
Cloud Computing
IBM Japan
Tomoyuki Niijima

2. © 2019 IBM Corporation
Direct Link Overview
▪ IBM Cloud offers Direct Link services to allow customers to establish private connectivity
from their premise.
▪ There are the following types.
– Direct Link Exchange
• Single connection over Exchange service provided at PoP by 3rd party service
providers such as ECX (Equinix Cloud Exchange). Cost effective solution especially
for those who will connect multiple clouds.
– Direct Link Connect
• Provided by partnership with various carriers.
– Direct Link Dedicated
• Use this if you need a dedicated port
• Use this if you need a connection at a DC location
CAUTION: Now BGP is mandatory to manage routing via Direct Link. An account that orders
Direct Link will be migrated to VRF environment. (See P.14 - 16 for details) Inter-account
VLAN spanning will not be allowed in VRF environment. VPN service will be limited.
You can configure redundant links by ordering two Direct Links. (See P.17)
There is another type called Direct Link Dedicated Hosting which offers racks and cross
connects. Direct Link Dedicated Hosting is out of the scope of this document.
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3. © 2019 IBM Corporation3
Direct Link Exchange overview
▪ Single connection over Exchange service provided at PoP by 3rd party service providers
such as ECX (Equinix Cloud Exchange) or Verison.
▪ Customers needs to cover process and cost to establish connect from their premise to the
data center where a target PoP is located, including that of exchange service.
▪ Typically requires 30 to 60 days to complete the link.
▪ 50M, 100M, 200M, 500M, 1G, 2G and 5Gbps speeds are available.
▪ Subnets required in between routers will be provided by IBM Cloud.
▪ 1000BASE-LX or10GBASE-LR, both with single mode fibre will be used for the link.
▪ VLAN trunking of 802.1Q or 802.1ad will be used.
Customer
PoP
DC of a PoP IBM Cloud
DC
BCR
VM
Private VLAN
Public VLAN
Internet
CX
802.1Q
Or
802.1ad
802.1Q
Customer’s responsibility IBM Cloud’s responsibility
CER XCR
BGP
VC

4. © 2019 IBM Corporation4
Direct Link Exchange ordering process
1. Sign up for IBM Cloud.
2. Order a server on IBM Cloud to find a subnet on a Private VLAN.
3. Order the following to the exchange service provider such as Equinix.
– Co-location space to install the customer’s router at PoP location
– Exchange service such as ECX
– Cross connect to the exchange service
4. Order a Direct Link for Cloud to confirm connection parameters such as Service Key, CID, IP address
and BGP ASN.
5. Request IBM Cloud to migrate the account to VRF. (As for link through ECX, the case will be closed at
this stage and encouraged to reorder through the process on the next page.)
6. Order a VC to the exchange provider.
1. Specify VLAN type
2. Specify VLAN ID for the customer’ s side
3. Specify the ticket number of the Direct Link order as a Service Key and CID.
4. Notify IBM Cloud of the VC order completion.
7. Configure the customer’s side router.
8. Verify connectivity in between CERs and XCRs.
9. Configure NAT gateway or GRE tunnels based on a design.
10. Verify end to end testing.
11. Notify completion of the connection via ticket.
12. Charge for the link will be started.

5. © 2019 IBM Corporation5
Direct Link Exchange ordering process (using automation for ECX)
Before following the process;
VRF migration of the account must be completed.
ECX account must be ready.
1. Order a Direct Link Exchange
2. Confirm provided IP addresses and a service key, IBM port name, and BGP ASN.
3. Order a VC to the exchange providre.
1. Specify VLAN type
2. Specify VLAN ID for the customer’ s side
3. Specify the request ID using the value of service key provided at step 2.
4. Specify the buyer’s port which match with the IBM port name. (See P.7)
VC will be accepted automatically. If the provider status of a VC won’t be available within a
day, you will need to open a case on the IBM Cloud portal to fix it.
4. Configure the customer’s side router.
5. Verify connectivity in between CERs and XCRs after VC will be connected status.
6. Configure NAT gateway or GRE tunnels based on a design.
7. Verify end to end testing.

6. © 2019 IBM Corporation6
Direct Link Exchange physical wiring
▪ From customer’s premise to the target PoP
– Remote network from the customer’s premise to the target PoP location will be provided
by a carrier, and co-location space at the data center will be provided by a data center
provider, based on the customer’s order.
▪ In house connection at the target DC
– 1000BASE-LX or 10GBASE-LR with single mode fibre
– The customer is responsible to the customer’s side connection.
– From the customer’s rack to the exchange service will be connected by a data center
provider based on the customer’s order.
– Connection in between the exchange service and IBM Cloud is done by IBM Cloud.
– Redundant link will need two links. Exchange service providers and IBM Cloud has two
links in between two pair of equipments.
IBM Cloud DC
A Data center of a PoP location
CX
Remote lines
To customer’s place
IBM Cloud’s
responsibility
IBM Cloud PoP
CER01 XCR01
CER02 XCR02
Customer’s
responsibility

7. © 2019 IBM Corporation7
Direct Link Exchange: ports of ECX
▪ ECX has two service nodes, SE01 and SE02 in each location.
▪ There are a pair of links in between ECX and IBM Cloud using two seller’s ports. XCR01 is connected to
SE01 via the primary seller’s port, XCR02 is to SE02 via the secondary seller’s port.
▪ Name of two seller’s ports includes -PRI- or -SEC- as the following example.
– SOFTLAYER-TY2-CX-PRI-01
– SOFTLAYER-TY2-CX-SEC-01
▪ Customers can not specify a seller’s port when they order their first Direct Link Exchange via ECX at a
PoP, but they can see the assigned port name on the edit screen of the link, that can be opened by using
action > edit on the list of Direct Link Exchange.
▪ Customers can specify a seller’s port when they order their second or newer links on the order screen.
They can also confirm number of existing link on each ports.
▪ Customers will need to carefully specify a seller’s port so that two links will be provisioned on separate
XCRs.
▪ They will also use the port information to properly specify buyer’s port when they order a VC for each link.
Please be noted that buyer’s port with a name including -PRI- is not always connected to SE01. Please
verify mapping in between buyer’s ports and service nodes with Equinix.
CER01 XCR01
SE02
ECX
CER02 XCR02
SE01
Seller’s portBuyer’s port
-PRI-
-SEC-
-PRI-
-SEC-

8. © 2019 IBM Corporation
Direct Link Connect overview
▪ Provided by partnerships with carriers who offer network connectivity service with cloud
connectivity option.
▪ Physical connections in between IBM Cloud and partner carriers are already in place.
Customers can order virtual links with specified bandwidth.
▪ Customers must be existing user of those partner’s network connectivity service or will have
to order one of those network connectivity service.
▪ Typically requires 30 to 60 days to complete the link.
▪ 50M, 100M, 200M, 500M, 1G, 2G and 5Gbps speeds are available.
▪ Subnets required in between routers will be provided by IBM Cloud.
▪ Peer router of customer’s side will be a pair of PE routers managed by a carrier or
customer’s CER router depending on types of the network service. (See P.9)
▪ Availability of single or redundant link options depends on each partner’s service model.

9. © 2019 IBM Corporation9
Direct Link Connect overview (continued)
▪ Peer routers will be a pair of PE routers managed by carriers when the network service is
providing layer 3 network.
▪ Peer routers will be a pair of CER routers when the network service is providing layer 2
network.
List of L2 and L3 carriers: https://cloud.ibm.com/docs/infrastructure/direct-link?topic=direct-link-comparing-layer-2-layer-3
Users
PECE XCR
PoP
IBM Cloud DC
BCR
VM
Private VLAN
Public VLAN
Internet
Customer’s scope IBM’s scope
BGP
VC
Carrier’s
L3
Network
Users
SWCER XCR
PoP
IBM Cloud DC
BCR
VM
Private VLAN
Public VLAN
Internet
Customer’s scope IBM’s scope
BGP
VC
Users
CE
Carrier’s L2 Network

10. © 2019 IBM Corporation10
Direct Link Dedicated overview
▪ Customers needs to cover process and cost to establish connect from their premise to the
data center where a target PoP is located, including that of cross connect.
▪ Typically requires 30 to 60 days to complete the link.
▪ 1G, 2G, 5G and 10Gbps speeds are available.
▪ Subnets required in between routers will be provided by IBM Cloud.
▪ 1000BASE-LX or10GBASE-LR, both with single mode fibre will be used for the link.
Customer
NAT
PoP
Data Center
IBM Cloud
Data center
BCR
VM
Private VLAN
Public VLAN
Internet
Customer’s responsibility IBM Cloud’s responsibility
CER XCRBGP

11. © 2019 IBM Corporation11
Direct Link Dedicated ordering process
1. Sign up for IBM Cloud.
2. Order a server on IBM Cloud to find a subnet on a Private VLAN.
3. Order a co-location space to install the customer’s router at PoP location
4. Order a Direct Link Dedicated to get LOA (Letter of Agreement) and other information.
5. Order connections from customer’s premise to the data center.
6. Order cross connects to the data center provider.
7. Configure the customer’s router (CER).
8. Send IBM Cloud a completion notice for the cross connects issued by the data center
provider via a ticket of the Direct Link order.
9. Verify connectivity in between CER and XCR.
10.Configure NAT gateway or GRE tunnels based on a design.
11.Verify end to end testing.
12.Notify completion of the connection via ticket.
13.Charge for the link will be started.

12. © 2019 IBM Corporation12
Direct Link Dedicated physical wiring
▪ From customer’s premise to the target PoP location
– Remote network from the customer’s premise to the target PoP location will be provided
by a carrier, and co-location space at the data center will be provided by a data center
provider, based on the customer’s order.
▪ In house connection at the target PoP location
– 1000BASE-LX or 10GBASE-LR with single mode fibre
– The customer is responsible to the customer’s side connection.
– From the customer’s rack to IBM Cloud’s patch panel will be connected by a data center
provider based on the customer’s order.
– IBM Cloud is responsible to connect from IBM Cloud’s side patch panels to IBM Cloud’s
routers.
CER
Patch panel
XCR
Patch panel
A Data center of a
PoP locationCustomer’s
responsibility
IBM Cloud’s
responsibility
IBM Cloud PoP
IBM Cloud DC
Remote lines
To customer’s place

13. © 2019 IBM Corporation13
Contracts and payments around PoP/DC
▪ Remote connection
– Carrier will provide a quote
– Data center provider will provide a quote for a co-location space to install customer’s
routers.
▪ Cross connect at PoP/DC
– Data center provider will provide a quote for cross connects
▪ Direct Link
– Direct Link should be ordered on the IBM Cloud portal
Customer
NAT
IBM Cloud’s scope
VM
Private VLAN
Public VLAN
Internet
Customer’s responsibility IBM Cloud’s responsibility
CER XCR

14. © 2019 IBM Corporation14
Direct Link routing
▪ A customer’s router at PoP/DC is called as CER (Customer’s Endpoint Router). A IBM
Cloud’s side router is called as XCR (Cross Connect Router).
▪ IBM Cloud provides subnet (10.254.x.x/31*) in between CER and XCR.
▪ VRF environment will be configured around XCR and BCR which enables routing from the
private VLAN to the customer’s network.
▪ BGP need to be configured in between CER and XCR.
▪ CER advertise routes to customer’s network to XCR, XCR advertise IBM Cloud’s network to
CER.
▪ CER is inhibited to advertise the following subnets which is reserved by IBM Cloud.
10.0.0.0/14, 10.200.0.0/14, 10.198.0.0/15, 169.254.0.0/16, 224.0.0.0/4
Subnet for Direct Link (/31 or /30 size subnet from 10.254.0.0/16 range)
Subnets on Private VLANs
CER BCR
Private VLAN
Public VLAN
VM
XCR
10.254.x.x/31*
VRF
Customer
IBM Cloud scope
Customer’s address IBM Cloud’s address
*Request /30 subnet if CER will not support /30.
Alternative address or range (172.16.0.0/12) can
be requested if the assigned subnet won’t work.

15. © 2019 IBM Corporation15
Direct Link: some more details about BGP use
1. What AS number can be used?
IBM Cloud’s ASN is 13884, for both public and private. IBM Cloud will specify private ASNs
as AS PATH attribute for each route advertisements from the range of 65200-65235 and
65400-65435.
Customer can use public ASN (1 - 64495) or a private ASN 64999 or a 4byte Private ASN
between 4201000000 to 4201064511.
2. How IBM Cloud advertises routes through BGP from XCR to CER?
For each private subnets on Private VLANs that are assigned to the account and should
be reachable through the Direct Link will be advertised.
3. Which attributes are supported?
Well-known mandatory and Well-known discretionary are supported.
4. Supported capabilities?
The following capabilities are confirmed to be supported. XCR will just ignore non-
supported capabilities sent through a BGP session and will keep the session.
Multi protocol Extensions Capability (address family IPv4 unicast only)
Route-Refresh Capability
4 Octets-AS Capability
5. keepalive/hold timer setting?
keepalive 30sec / hold time 90sec

16. © 2019 IBM Corporation16
Direct Link routing (optional)
Address conflict in between customer’s network and IBM Cloud network may be avoided by
the following method.
▪ Configure GW using VRA or Linux server on IBM Cloud.
▪ Establish GRE or IPsec tunnel in between GW and CER, or a router that can be reachable
by using a route which is advertised in BGP.
▪ Use customer’s address from customer’s side up to GW through the tunnel, use IBM Cloud’s
address from CER to IBM Cloud side out side of the tunnel.
▪ NAT still may be required at GW depending on IP addresses involved on both end.
CER
Private VLAN
Public VLAN
VMGW
NAT
XCR
10.254.x.x/31Customer
IBM Cloud scope
Customer’s address
IBM Cloud’s address
BGP
GRE tunnel

17. © 2019 IBM Corporation17
Direct Link: Redundant path configuration
1. Any of Direct Link Exchange, Direct Link Connect, and Direct Link Dedicated will provide single link for
each one order.
2. Some carriers require 2 Direct Link Connect orders at the same PoP.
3. Other than the case in 2., any two or more Direct Links can be used to configure redundant path.
4. An recommended method is to configure active/standby path using BGP AS PATH.
a. Configure primary CER to advertise routes with AS PATH=64999, while secondary CER to
configure to advertise the same routes with AS PATH=“64999 64999”.
b. This will route packets from IBM Cloud to on-premise via primary CER when the primary is
available and route them via secondary when the primary down.
c. Path from from on-premise to IBM Cloud is typically managed by having a virtual gateway address
in between primary and secondary CERs on their interfaces for the on-premise side.
5. All the XCRs will advertise the same routes for all the private subnets to each peer CER.
CER1
CER2
XCR1
XCR2
IBM Cloud
Customer’s
Network
BGPgateway
address
AS PATH=64999
AS PATH=“64999 64999”
AS 13884AS 64999

18. © 2019 IBM Corporation
References
▪ IBM Cloud / Direct Link
https://cloud.ibm.com/docs/direct-link
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