T5916: Added segment routing check for index base size and SRGB base size

(cherry picked from commit cfb5b052c84ffba789d61a59350676b6b4a0a5f7)

1 files changed, 14 insertions, 1 deletions

diff --git a/src/conf_mode/protocols_isis.py b/src/conf_mode/protocols_isis.py
index ce67ccff7..8d594bb68 100755
--- a/src/conf_mode/protocols_isis.py
+++ b/src/conf_mode/protocols_isis.py
@@ -220,7 +220,20 @@ def verify(isis):
                 if ("explicit_null" in prefix_config['index']) and ("no_php_flag" in prefix_config['index']):
                     raise ConfigError(f'Segment routing prefix {prefix} cannot have both explicit-null '\
                                       f'and no-php-flag configured at the same time.')
-                
+ 
+    # Check for index ranges being larger than the segment routing global block    
+    if dict_search('segment_routing.global_block', isis):
+        g_high_label_value = dict_search('segment_routing.global_block.high_label_value', isis)
+        g_low_label_value = dict_search('segment_routing.global_block.low_label_value', isis)
+        g_label_difference = int(g_high_label_value) - int(g_low_label_value)
+        if dict_search('segment_routing.prefix', isis):
+            for prefix, prefix_config in isis['segment_routing']['prefix'].items():
+                if 'index' in prefix_config:
+                    index_size = isis['segment_routing']['prefix'][prefix]['index']['value']
+                    if int(index_size) > int(g_label_difference):
+                        raise ConfigError(f'Segment routing prefix {prefix} cannot have an '\
+                                          f'index base size larger than the SRGB label base.')
+            
     # Check for LFA tiebreaker index duplication
     if dict_search('fast_reroute.lfa.local.tiebreaker', isis):
         comparison_dictionary = {}