Copy as Markdown / Cisco Exports¶

Every result panel in the Subnet Calculator (IPv4, IPv6, VLSM, IPv6 VLSM, IPv4 splitter, IPv6 splitter) renders three small buttons next to Copy All:

Copy as Markdown — emits a Markdown table you can paste into a ticket, a runbook, a Confluence page, or any Markdown-aware editor.
Copy as Cisco — emits a generic Cisco IOS-style snippet you can paste into a router/switch console as a starting point for a real config.

Both buttons use the system clipboard via navigator.clipboard.writeText() and fall back to a hidden <textarea> + document.execCommand('copy') in cross-origin iframes where the async clipboard API is unavailable.

When to use each format¶

Format	Good for	Not for
Markdown	tickets (Jira, Linear, GitHub Issues), runbooks, Confluence/Notion pages, change records, architecture docs	direct paste into device config
Cisco	starter snippet for IOS / IOS-XE / NX-OS, scaffolding a config for a new device, copy-into-lab workflows	drop-in production config; non-Cisco vendors without edits

IPv4 result panel¶

Markdown:

| Field | Value |
| --- | --- |
| Subnet (CIDR) | 192.168.1.0/24 |
| Netmask (CIDR) | /24 |
| Netmask (Octet) | 255.255.255.0 |
| Wildcard Mask | 0.0.0.255 |
| First Usable IP | 192.168.1.1 |
| Last Usable IP | 192.168.1.254 |
| Broadcast IP | 192.168.1.255 |
| Usable IPs | 254 |
| Address Type | Private |
| Reverse DNS Zone | 1.168.192.in-addr.arpa |

Cisco:

! Generic Cisco IOS-style configuration
! Generated by Subnet Calculator — vendor-specific tweaks may apply

interface GigabitEthernet0/0
 description IPv4 192.168.1.0/24
 ip address 192.168.1.0 255.255.255.0
 no shutdown
!

IPv6 result panel¶

Markdown:

| Field | Value |
| --- | --- |
| Network (CIDR) | 2001:db8::/32 |
| Prefix Length | /32 |
| First IP | 2001:db8:: |
| Last IP | 2001:db8:ffff:ffff:ffff:ffff:ffff:ffff |
| Total Addresses | 2^96 |
| Address Type | Documentation |
| Reverse DNS Zone | 8.b.d.0.1.0.0.2.ip6.arpa |

Cisco:

! Generic Cisco IOS-style configuration
! Generated by Subnet Calculator — vendor-specific tweaks may apply

interface GigabitEthernet0/0
 description IPv6 2001:db8::/32
 ipv6 address 2001:db8::/32
 no shutdown
!

VLSM (IPv4)¶

Markdown table includes Name, Hosts Needed, Allocated Subnet, Usable IPs, Waste:

| Name | Hosts Needed | Allocated Subnet | Usable IPs | Waste |
| --- | --- | --- | --- | --- |
| LAN A | 50 | 10.0.0.0/26 | 62 | 12 |
| LAN B | 25 | 10.0.0.64/27 | 30 | 5 |

Cisco emits one interface stanza per allocation, using the VLSM allocation name as the description and the first usable host as the interface IP:

! Generic Cisco IOS-style configuration
! Generated by Subnet Calculator — vendor-specific tweaks may apply

interface GigabitEthernet0/0
 description LAN-A
 ip address 10.0.0.1 255.255.255.192
 no shutdown
!
interface GigabitEthernet0/1
 description LAN-B
 ip address 10.0.0.65 255.255.255.224
 no shutdown
!

VLSM (IPv6)¶

Same Markdown structure, ordered Name / Hosts Needed / Allocated Subnet / Usable Addresses. Cisco output uses ipv6 address with the full prefix:

interface GigabitEthernet0/0
 description LAN-A
 ipv6 address 2001:db8::/64
 no shutdown
!

IPv4 splitter¶

Markdown numbers each split subnet:

| # | Subnet |
| --- | --- |
| 1 | 192.168.0.0/26 |
| 2 | 192.168.0.64/26 |
| 3 | 192.168.0.128/26 |
| 4 | 192.168.0.192/26 |

Cisco emits one stanza per split subnet (description Split-N):

interface GigabitEthernet0/0
 description Split-1
 ip address 192.168.0.0 255.255.255.192
 no shutdown
!

IPv6 splitter¶

Same as IPv4 splitter but uses ipv6 address and the full prefix per stanza.

Caveats and limitations¶

Cisco output is intentionally generic IOS-style. Interface names default to GigabitEthernet0/N (zero-indexed). Adjust to your actual interface inventory (TenGigE, Ethernet1/1, Loopback0, etc.) before applying.
Not vendor-portable. Juniper (set interfaces …), Arista EOS (largely IOS-compatible but uses Ethernet numbering), Mikrotik RouterOS (/ip address add), and others use different syntax. Treat the export as a starting point, not a drop-in config.
First-usable IP for VLSM IPv4 is what gets configured on the interface — change to whatever host address fits your addressing convention (often .1 of the subnet) before applying.
No defaults are emitted for interface description text beyond the VLSM allocation name (slugified) or the kind label. If you need consistent descriptions across a fleet, edit before commit.
No ACLs, routing, or VRF context is generated. The export is interface-stanza only.

Where the buttons live¶

The buttons are inline next to Copy All in each result panel. On viewports narrower than 480px they wrap onto multiple rows automatically. Each Copy as Cisco button has a help bubble explaining the IOS-style caveat.