03-20-2020 07:38 AM
Hello,
I am configuring the handoff part of the SD-Access for my customer.
To summarize, we have the following VRF/VN :
- GRT/DEFAULT_VN : Underlay
- Corporate_VN
For GRT/DEFAULT_VN and Corporate_VN, the eBGP will finish on fusion routers (catalyst 9500)
1- According to cisco documents, I have initially configured BGP on fusion routers with "maximum-path 2" parameter. But on Border, DNAC do not configure that for the VRF. Do I have to manually add this parameter for each address-family on borders ?
2- On Borders nodes, interconnection subnets (/30) for each VRF are annonced on BGP with network command. For me, it is useless. According to cisco documents, initial configuration of the border (GRT) do not announced interconnection subnets (/30) in GRT.
3- For redundancy, is therebest practices about BGP timers ?
Many thanks for your help.
Regards,
Hugo
Solved! Go to Solution.
03-24-2020 08:32 AM
I'll answer your questions inline below:
1- According to cisco documents, I have initially configured BGP on fusion routers with "maximum-path 2" parameter. But on Border, DNAC do not configure that for the VRF. Do I have to manually add this parameter for each address-family on borders ?
ChuckMcF: We manually configured ours (maximum-paths eibgp 2 since our EBNs are connected via iBGP and FRs are eBGP). For clarity, we have dual FR and dual EBNs in our SDA network.
2- On Borders nodes, interconnection subnets (/30) for each VRF are annonced on BGP with network command. For me, it is useless. According to cisco documents, initial configuration of the border (GRT) do not announced interconnection subnets (/30) in GRT.
ChuckMcF:we do not have interconnects advertised via network statements. I agree, no point. The only network statements are for those networks in the specific VRFs.
3- For redundancy, is therebest practices about BGP timers ?
ChuckMcF: my suggestion would be to leave timers alone and use BFD.
VLAN xxxx
bfd interval 100 min_rx 100 multiplier 3
router bgp xxxxx
neighbor a.b.c.d fall-over bfd
HTH,
Chuck McFadden
03-25-2020 04:44 PM
Do I have to manually add this parameter for each address-family on borders ?
It depends, you only need this command if you have more than one link. If your Border and Fusion have single connections, you don't need to worry about it.
2- On Borders nodes, interconnection subnets (/30) for each VRF are annonced on BGP with network command. For me, it is useless. According to cisco documents, initial configuration of the border (GRT) do not announced interconnection subnets (/30) in GRT.
EBGP next hop is changed, iBGP isn't. So that's one thing to consider. If you're using EBGP, the /30's are really only handy for testing. I.E, if you want to ping from one /30 to another /30, you'd need those routes end to end. Going back in to your Shared Ssrvices though, you really need the /32's from each router within your Fabric Domain.
3- For redundancy, is therebest practices about BGP timers ?
If you own the access network, you can set these really low, plus add BFD.
03-24-2020 08:32 AM
I'll answer your questions inline below:
1- According to cisco documents, I have initially configured BGP on fusion routers with "maximum-path 2" parameter. But on Border, DNAC do not configure that for the VRF. Do I have to manually add this parameter for each address-family on borders ?
ChuckMcF: We manually configured ours (maximum-paths eibgp 2 since our EBNs are connected via iBGP and FRs are eBGP). For clarity, we have dual FR and dual EBNs in our SDA network.
2- On Borders nodes, interconnection subnets (/30) for each VRF are annonced on BGP with network command. For me, it is useless. According to cisco documents, initial configuration of the border (GRT) do not announced interconnection subnets (/30) in GRT.
ChuckMcF:we do not have interconnects advertised via network statements. I agree, no point. The only network statements are for those networks in the specific VRFs.
3- For redundancy, is therebest practices about BGP timers ?
ChuckMcF: my suggestion would be to leave timers alone and use BFD.
VLAN xxxx
bfd interval 100 min_rx 100 multiplier 3
router bgp xxxxx
neighbor a.b.c.d fall-over bfd
HTH,
Chuck McFadden
03-26-2020 02:25 AM
Many thanks for these clarifications.
03-25-2020 04:44 PM
Do I have to manually add this parameter for each address-family on borders ?
It depends, you only need this command if you have more than one link. If your Border and Fusion have single connections, you don't need to worry about it.
2- On Borders nodes, interconnection subnets (/30) for each VRF are annonced on BGP with network command. For me, it is useless. According to cisco documents, initial configuration of the border (GRT) do not announced interconnection subnets (/30) in GRT.
EBGP next hop is changed, iBGP isn't. So that's one thing to consider. If you're using EBGP, the /30's are really only handy for testing. I.E, if you want to ping from one /30 to another /30, you'd need those routes end to end. Going back in to your Shared Ssrvices though, you really need the /32's from each router within your Fabric Domain.
3- For redundancy, is therebest practices about BGP timers ?
If you own the access network, you can set these really low, plus add BFD.
03-26-2020 02:26 AM
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: